SQL Commands Reference

Transcription

1 C:\Program Files\Adobe\FrameMaker8\UniData 7.2\7.2rebranded\SQLREF\SQLRTITL.fm March 9, :05 pm Beta Beta Beta Beta Beta Beta Beta Beta Beta Beta Beta Beta Beta Beta Beta Beta UniData SQL Commands Reference UDT-720-SQLR-1

2 C:\Program Files\Adobe\FrameMaker8\UniData 7.2\7.2rebranded\SQLREF\SQLRTITL.fm March 9, :05 pm Beta Beta Beta Beta Beta Beta Beta Beta Beta Beta Beta Beta Beta Notices Edition Publication date: July 2008 Book number: UDT-720-SQLR-1 Product version: UniData 7.2 Copyright Rocket Software, Inc All Rights Reserved. Trademarks The following trademarks appear in this publication: Trademark Rocket Software Dynamic Connect RedBack SystemBuilder UniData UniVerse U2 U2.NET U2 Web Development Environment wintegrate Microsoft.NET Microsoft Office Excel, Outlook, Word Windows Windows 7 Windows Vista Java and all Java-based trademarks and logos UNIX Trademark Owner Rocket Software, Inc. Rocket Software, Inc. Rocket Software, Inc. Rocket Software, Inc. Rocket Software, Inc. Rocket Software, Inc. Rocket Software, Inc. Rocket Software, Inc. Rocket Software, Inc. Rocket Software, Inc. Microsoft Corporation Microsoft Corporation Microsoft Corporation Microsoft Corporation Microsoft Corporation Sun Microsystems, Inc. X/Open Company Limited ii UniData SQL Commands Reference

3 The above trademarks are property of the specified companies in the United States, other countries, or both. All other products or services mentioned in this document may be covered by the trademarks, service marks, or product names as designated by the companies who own or market them. License agreement This software and the associated documentation are proprietary and confidential to Rocket Software, Inc., are furnished under license, and may be used and copied only in accordance with the terms of such license and with the inclusion of the copyright notice. This software and any copies thereof may not be provided or otherwise made available to any other person. No title to or ownership of the software and associated documentation is hereby transferred. Any unauthorized use or reproduction of this software or documentation may be subject to civil or criminal liability. The information in the software and documentation is subject to change and should not be construed as a commitment by Rocket Software, Inc. Restricted rights notice for license to the U.S. Government: Use, reproduction, or disclosure is subject to restrictions as stated in the Rights in Technical Data- General clause (alternate III), in FAR section All title and ownership in this computer software remain with Rocket Software, Inc. Note This product may contain encryption technology. Many countries prohibit or restrict the use, import, or export of encryption technologies, and current use, import, and export regulations should be followed when exporting this product. Please be aware: Any images or indications reflecting ownership or branding of the product(s) documented herein may or may not reflect the current legal ownership of the intellectual property rights associated with such product(s). All right and title to the product(s) documented herein belong solely to Rocket Software, Inc. and its subsidiaries, notwithstanding any notices (including screen captures) or any other indications to the contrary. Contact information Rocket Software 275 Grove Street Suite Newton, MA USA Tel: (617) Fax: (617) Web Site: UniData SQL Commands Reference iii

4 Beta Beta Beta Beta Beta Beta Beta Beta Beta Beta Beta Beta Beta Beta Beta Beta Table of Contents Table of Contents Chapter 1 UniData SQL Commands Commands Summary UniData SQL Limitations ALTER TABLE AUTO COMMIT BREAK BTITLE CLEAR COLUMN COMMIT COMO COMPUTE CREATE INDEX CREATE SUBTABLE CREATE TABLE CREATE VIEW DELETE DROP INDEX DROP SUBTABLE DROP TABLE DROP VIEW EXIT GRANT INSERT LISTDICT LOCK TABLE QUIT REVOKE ROLLBACK SELECT SET SHOW \Program Files\Adobe\FrameMaker8\UniData 7.2\7.2rebranded\SQLREF\SQLRTOC.fm (booktoc.template)

5 SQL TTITLE UPDATE Adding Multivalues and Multi-Subvalues Examples Appendix A Appendix B Appendix C Defining Attributes Default Format and Conversion Codes A-2 Attribute Name A-3 Data Type A-4 CHAR A-4 DATE A-5 NUMBER A-5 LONG A-6 Virtual Attributes (IDESC or VIRTUAL) A-10 Location (LOC) A-11 Display Name (DISP) A-12 FORMAT A-13 Value Code Specification A-15 SM A-15 Associating Attributes A-16 Unnesting Attributes Unnesting Associated Attributes B-2 Sample Table for Unnesting Examples B-2 Unnesting Associated Multivalued Attributes B-4 Unnesting Associated Multi-Subvalued Attributes B-5 Unnesting All Attributes in an Association B-6 Unnesting Unassociated Attributes B-8 Creating Subtables Base Tables C-2 T_CLIENTS C-3 T_INVENTORY C-4 T_ORDERS C-5 CREATE SUBTABLE Examples C-7 T_CLIENTS NL0 Subtables C-7 T_CLIENTS NL1 Subtables C-8 T_INVENTORY NL0 Subtable C-9 T_INVENTORY NL1 Subtables C-9 Table of Contents v

6 T_ORDERS NL0 Subtables C-13 T_ORDERS NL1 Subtables C-14 T_ORDERS NL2 Subtables C-18 Appendix D Arithmetic Functions and Operators Arithmetic Functions D-2 Arithmetic Operators D-3 vi UniData SQL Commands Reference

7 UniData SQL Commands This chapter provides complete descriptions of all commands in the UniData implementation of Structured Query Language (SQL). UniData SQL commands can be entered from the sql prompt or by encoding a series of SQL statements in an ASCII text file (UniData SQL script) with your system editor. You can then execute the script from the operating system prompt. This provides the capability of reusing a series of UniData SQL statements. 1-1

8 Elements of Syntax Statements This reference manual uses a common method for stating syntax for UniData commands. The syntax statement includes the command name, required arguments, and options that you can use with the command. Italics represents a variable that you can replace with any valid option. The following figure illustrates the elements of a syntax statement. command names appear in boldface square brackets indicate an optional argument no brackets or braces indicates a required argument a vertical line indicates that you may choose between the given arguments COMMAND required [option] [option1 option2] {option1 option2} required... "string" quotation marks must enclose a literal string braces indicate that you must choose between the given arguments an ellipsis indicates that you may enter more than one argument 1-2 UniData SQL Commands Reference

9 Elements of UniData SQL Commands Summary Data Definition Language (DDL) Data definition language is also called schema definition. It uses table, indexing, view, and subtable commands. Table Commands: CREATE TABLE ALTER TABLE DROP TABLE Indexing Commands: CREATE INDEX DROP INDEX View Commands: CREATE VIEW DROP VIEW Subtable Commands: CREATE SUBTABLE DROP SUBTABLE Data Control Language (DCL) Data control language is also called connection management. It uses privilege and transaction processing commands. 1-3

10 Privilege Commands: GRANT REVOKE Transaction Processing Commands: AUTO COMMIT COMMIT ROLLBACK LOCK TABLE SET DISPLAY SET TRANSACTION Data Manipulation Language (DML) INSERT SELECT UPDATE DELETE Report Commands (RPT) TTITLE BTITLE COLUMN COMPUTE BREAK CLEAR SET SHOW Supplementary Commands (SUP) SQL 1-4 UniData SQL Commands Reference

11 EXIT QUIT LISTDICT COMO 1-5

12 SELECT Statement Elements * ALL DISTINCT attributes functions expressions literals FROM UNNEST NL1, NL2, NL_ALL WHERE =,!=, <, <=, >, >=, <>,!<,!> EVERY subquery NOT IS [NOT] NULL [NOT] BETWEEN [NOT] IN [NOT] INTERSECT [NOT] LIKE %, _,..., na, nn, nx GROUP BY HAVING UNION ORDER BY TO INTO LPTR 1-6 UniData SQL Commands Reference

13 UniData SQL Limitations In a SELECT statement, you cannot select more than 1000 attributes. All identifiers in UniData SQL, such as table_name, view_name, attribute_name, table_label, and all variables in OLD/NEW_VALUE of the COLUMN statement can be no longer than 30 characters. A UniData SQL statement cannot exceed 49 lines. The length of a single line of a UniData SQL statement, when used interactively, cannot exceed 272 characters. A single association cannot exceed 64 attributes. A table can contain a maximum of 12 associations. SELECT statement or clause cannot contain more than 255 virtual attributes. The IN predicate cannot contain more than five operators. Each operator must be a constant. The length of each constant cannot exceed 95 characters. Within a WHERE clause, the total number of predicates and Boolean operators cannot exceed 255. The ORDER BY clause can contain no more than nine elements (attribute names, expressions, and ordinal positions). The number of tables in the FROM clause of a SELECT statement is limited to 16. However, when performing a join, a new temporary table is created internally for every two joined tables in the FROM clause. Therefore, a join can contain no more than eight join tables, whereas a nested subquery with exactly one table at every level may contain up to 16 levels. The UNNEST clause can process 10,240 values in a multivalued or multi-subvalued attribute, or in all associations for the unnested record. The number of elements (column names, expressions, and functions) in a select list cannot exceed

14 ALTER TABLE Syntax ALTER TABLE table_name {ADD MODIFY DELETE} (attribute_definition [,attribute_definition...]) ALTER TABLE table_name MODULO m[,n] Description Use the ALTER TABLE command to add, modify, or delete attribute definitions in a table or to change the modulo for a table. You cannot modify subtables with ALTER TABLE; you must delete and re-create them. Note: attribute_definition syntax is fully described in Appendix A, Defining Attributes. When you use ALTER TABLE to modify or delete attribute_location, UniData SQL changes the dictionary entry for the attribute, which may make one or more attributes inaccessible (changing attribute location, for example). If you later add back the attribute at the same location, the data again becomes accessible. You must update/reindex if you modify an indexed attribute. Keywords The following table describes keywords you can use with ALTER TABLE. Keyword ADD Description Add an attribute definition to a table. ALTER TABLE Keywords 1-8 UniData SQL Commands Reference

15 Keyword MODIFY DELETE Description Change the definition of an attribute in a table. Delete an attribute definition from a table. MODULO Change the modulo size/block size of a table. Controls the size of the table by assigning block size and number of blocks to store the data. ALTER TABLE Keywords (continued) The parameters for ALTER TABLE are described under CREATE TABLE. Exceptions and additions to these descriptions are noted in the following sections. ALTER TABLE ADD The ADD keyword creates a new attribute definition or alias. If no location is specified, the new attribute is assigned the next available location. Syntax: ALTER TABLE table_name ADD (attribute_definition [, attribute_definition]...) Parameters table_name is the name of the table to be modified. For a description of attribute_definition, see Appendix A, Defining Attributes. Example: ALTER TABLE ADD sql> ALTER TABLE ORDERS ADD sql> (CATEGORY CHAR(10)); 1 attribute(s) added. ALTER TABLE MODIFY The MODIFY keyword modifies only the characteristics of the attribute you specify; other characteristics of the attribute remain the same. Note that UniData may update associations affected by the changes you make. The attribute you specify in the MODIFY clause must already exist in the dictionary; if it does not, UniData SQL displays an error message. 1-9

16 You can modify any characteristic of an attribute definition except the location of attribute. Syntax: ALTER TABLE table_name MODIFY (attribute_definition [, attribute_definition]...) table_name is the name of the table to be modified. For a description of attribute_definition, see Appendix A, Defining Attributes. Data type in attribute_definition is optional for ALTER TABLE MODIFY. Parameters For a description of table_name, see CREATE TABLE. For a description of attribute_definition, see Appendix A, Defining Attributes. Modifying Association Names When you modify the association name of an attribute, UniData SQL makes corresponding changes to the PH attribute. If you add a new association name to an attribute definition, UniData SQL creates a phrase attribute for that name and puts the related attribute name into the phrase of the PH attribute. If you add an existing association name to an attribute definition, UniData SQL adds the attribute name to the phrase of the PH attribute. If you remove the association name from an attribute definition, UniData SQL deletes that attribute name from the phrase of the associated PH attribute. If you remove the association name and it is not used in any other attribute definitions, UniData SQL deletes the association attribute (PH) from the dictionary. Example: ALTER TABLE MODIFY The following example demonstrates modifying the ORDERS table by adding a display name for the CLIENT_NO attribute: sql> ALTER TABLE ORDERS MODIFY sql> (CLIENT_NO DISP("Client No.")); 1 attribute(s) modified UniData SQL Commands Reference

17 ALTER TABLE DELETE The DELETE keyword deletes an attribute definition or alias. You cannot delete of the table unless it has at least one alias. Syntax: ALTER TABLE table_ spec DELETE (attribute_name[, attribute_name]...) ALTER TABLE DELETE deletes the attribute definition, making the data inaccessible. If you later add an attribute at the same location, the data again becomes accessible. table_name is the name of the table to be modified. For a description of attribute_definition, see Appendix A, Defining Attributes. Examples: ALTER TABLE DELETE This example demonstrates deleting PRICE from the ORDERS table: sql> ALTER TABLE ORDERS DELETE (PRICE); 1 attribute(s) deleted. In the following example, is deleted from the ORDERS table, making the data in that attribute inaccessible. Notice that can be deleted because an alias exists in the ORDERS file for this attribute; the data are still accessible through this alias. sql> ALTER TABLE ORDERS DELETE (@ID); 1 attribute(s) deleted. sql> FROM is not a field name. Transaction aborted. 1-11

18 Then, when is added back at the same location, the data is again accessible through that attribute name. sql> ALTER TABLE ORDERS ADD NUMBER LOC(0)); 1 attribute(s) added. sql> FROM ORDERS; Page ALTER TABLE MODULO The MODULO keyword resizes a static table. Disk space is reallocated based on the new MODULO. Assigning a new modulo physically rebuilds the file. Syntax: ALTER TABLE table_name MODULO m [,n] Parameters table_name is the name of the table to be modified. For instructions on setting MODULO, see CREATE TABLE. Example sql> ALTER TABLE CLIENTS MODULO 23; CLIENTS RESIZED from 19 to UniData SQL Commands Reference

19 AUTO COMMIT Syntax AUTO COMMIT [ ON OFF ] Description AUTO COMMIT ON causes each statement to commit immediately. AUTO COMMIT gives application developers and users enhanced transaction control capabilities. Parameters The following table describes each parameter of the syntax. Parameter ON OFF no option Description Each UniData SQL statement is immediately committed, releasing all locks. Several statements can be combined into one transaction. Use the OFF parameter if you want to be able to commit or roll back a set of statements as a single unit. Displays the current setting of AUTO COMMIT. AUTO COMMIT Parameters Note: Unlike SET TRANSACTION, which sets options that apply to the next transaction only, AUTO COMMIT affects all subsequent transactions until UniData SQL encounters another AUTO COMMIT statement. 1-13

20 Example The following example demonstrates the use of AUTO COMMIT to display or change its status: sql> AUTO COMMIT; Transaction auto commit option is ON. sql> AUTO COMMIT OFF; sql> AUTO COMMIT; Transaction auto commit option is OFF UniData SQL Commands Reference

21 BREAK Syntax BREAK ON {[attribute_name [ text VALUE] [NODUP DUPL] expression ["text" VALUE] [NODUP DUPL] ] ROW [BSKIP n] [SKIP n [SKIP] PAGE] REPORT [BSKIP n] [SKIP n [SKIP] PAGE] }... Description The BREAK command activates actions established by the COLUMN and COMPUTE commands, and adds printer directives to take place at the break. Both BREAK and COMPUTE must specify the same ON level, such as ON REPORT or ON fld1. A break may be associated with any of the following: A change in value of a specified attribute The end of a record The end of a report BREAK actions include the following: Skip a number of lines Execute a page break Print out messages Note: Only one break command can be in effect at one time. The last break command overrides the preceding one. 1-15

22 Parameters The following table describes each parameter of the syntax. Parameter ON attribute_name expression text VALUE NODUP DUPL ROW REPORT BSKIP n SKIP n SKIP PAGE no parameter Description Breaks when the value of the attribute or expression changes. An attribute name on which to execute break commands. Any combination of attribute names, constants, arithmetic operators, and UniData SQL functions that together select data. Expressions must be enclosed in quotation marks, and keywords must be entered in uppercase. Displays text at break. text must be enclosed in quotation marks. Displays the value of attribute_name or expression. Default. Prints only unique values. Prints duplicate values. Breaks after every record. Breaks at the end of the report. Skips n lines before printing the break line. Skips n lines after printing the break line. Skips to a new page after printing the break line. The keyword SKIP is optional. Displays the current break definition. BREAK Options 1-16 UniData SQL Commands Reference

23 Example The following example demonstrates the BREAK ON command, used to separate report information into a readable format. The break is set on PROD_NAME. Notice that the rows are also ordered by PROD_NAME so that all products of the same name are listed together. sql> BREAK ON PROD_NAME SKIP 1; sql> SELECT PROD_NAME, FEATURES, COLOR, ID FROM INVENTORY sql> UNNEST LINE_ITEMS sql> ORDER BY PROD_NAME, FEATURES; Page 1 Product Product Name Features Color Number Adapter A/C Adapter for notebook N/A computers Ethernet LC Card N/A Workgroup Hub N/A CD Player Personal Model, Bass Boost Gray Portable Model Black Portable Model Gray

24 BTITLE Syntax BTITLE [ print_clause OFF ON] print_clause syntax: {COL [n] LEFT CENTER RIGHT} [ text ] [FORMAT format [TAB [n] ] old_val text ]... Description The BTITLE command establishes a footer for printed and displayed reports created by SELECT statements. You can specify any number of constants and variables. These parameters are executed in the order in which they are defined. You can apply any number of BTITLE options to one or more attributes. If more than one BTITLE command is applied to the same attribute, the last command supersedes all previous commands. Note: Execute the SHOW BTITLE command to display the current setting of BTITLE UniData SQL Commands Reference

25 Parameters The following table describes each parameter of the syntax. Parameter print_clause ON OFF no parameter Description Sets the following: Skip columns. Skip lines. Align title data left, center or right. Format "text" for display. For print_clause options, see the next table. Turns the footer on, causing "text" to be printed. Turns the footer off. You do not have to redefine "text" to turn footers back on. Displays BTITLE current settings. SHOW BTITLE also displays current settings. BTITLE Parameters print_clause Parameters The following table describes each parameter of print_clause. Clause COL n Description Skips to the nth column before displaying the header. The first column is numbered 0. SKIP n Skips n lines before printing out the text. The default is 1. LEFT, CENTER, RIGHT Aligns the title data on the current line. The data item (variable or text) is aligned as a group to the end of the statement, or to the next LEFT, CENTER, or RIGHT, or to the next COL, SKIP, or TAB. CENTER and RIGHT are calculated based on the LINESIZE option of the SET statement. Print Clause Parameters 1-19

26 Clause FORMAT format old_val "text" TAB n Description Specifies a format model for the following data item. FORMAT is effective until the end of the statement or until another FORMAT clause is encountered in the same statement. format options are discussed following this table. Displays the current value of the variable old_val, set by OLD_VALUE in the previously executed COLUMN statement. Displays a two-line footer. The first line contains the date at the left and the page number on the right; the second line contains the centeraligned text. You can include any number of the following heading options enclosed in single quotation marks: C[n] Centers heading or footing text within a line of n width. D Inserts the current system date. L Inserts a blank line. N Suppresses the default prompt, Enter new line to continue..., that appears at the bottom of each screen page. Pages scroll without stopping until the report is finished. (The prompt displays only in interactive mode.) P or S Inserts the current page number. T Inserts the time and date when report generation began. Skips n columns from the current position. Print Clause Parameters (continued) format Options format specifies the display format for values in the footer. format must be enclosed in quotation marks, and can be one of the following: Character Format Options The format for a character string is An where n is the column width. The default is the length specified in the dictionary definition of the attribute. Date Format Options You may not specify format options for date attributes; the formatting specified in the dictionary definition of the attribute is used UniData SQL Commands Reference

27 Numeric Format Options Use the options in the following table to build a display mask for formatting numeric values. Option Explanation Example 9 Determines number of digits displayed Display leading zeros $ Prefix displayed value with a dollar sign. $9999 B Print leading zeros as blank. B999 MI Display minus sign (-) after a negative value. 9999MI PR Display a negative value in angle brackets 9999PR. Align on the decimal point , Insert a comma every three digits. 99,999 V EEEE Multiply the value by the n power of 10, where n is the number of 9s after V. Display the scientific notation (the format must contain four Es). format Numeric Options 999V EEEE Examples The following example demonstrates using the BTITLE command to learn its status. The preceding COLUMN command establishes the variable old_val, which is displayed in the BTITLE setting. sql> COLUMN PROD_NAME OLD_VALUE old_val; sql> BTITLE SKIP 2 COL 0 "Product:" TAB 15 old_val; sql> BTITLE ON; sql> BTITLE; Btitle is ON Btitle skip 2 col 0 'Product:' tab 15oldval 1-21

28 The next example demonstrates creating a header and footer, then displaying them by executing a SELECT statement. The SET PAGESIZE command causes the display page to be 10 lines long; SET LINESIZE establishes a 40-character-wide display area. sql> SET PAGESIZE 10; sql> SET LINESIZE 40; sql> TTITLE "Page TOP Title"; sql> BTITLE "Page BOTTOM Title"; sql> TTITLE ON; sql> BTITLE ON; sql> SELECT ID FROM ORDERS; The following is output from the preceding commands: Jun Page 1 Page TOP Title Order Number Page BOTTOM Title Enter <New line> to continue...q The next example demonstrates the following: SET LINESIZE to set the report width to 40 characters COLUMN...NEW_VALUE...OLD_VALUE to save the current and old value of PROD_NAME (from the INVENTORY table) TTITLE settings: SKIP 2 to skip two lines before displaying the report title (Product Prices) CENTER to center the report title (Product Prices) SKIP 2 to skip two lines before displaying the next title line (Product) TAB 2 to skip two spaces before printing the new value of PROD_NAME ON to turn the header on 1-22 UniData SQL Commands Reference

29 BTITLE settings: SKIP 2 to skip two lines before displaying the report footer (Product). COL 0 to skip 0 spaces (left-justify) the footer (Product). TAB 2 to skip two spaces before displaying the old value of PROD_NAME. ON to turn the footer on. sql>set LINESIZE 40; sql>column PROD_NAME sql>new_value newval sql>old_value oldval; sql>ttitle SKIP 2 sql>center "Product Prices" SKIP 2 sql>"product:" TAB 2 newval; sql>ttitle ON; sql>btitle SKIP 2 COL 0 "Product:" TAB 2 oldval; sql>btitle ON; 1-23

30 The following SELECT statement displays output formatted by the above commands. Notice that the first header does not display a product name after Product: because the variable old_val has not yet been assigned a value. sql>select ID, PROD_NAME, PRICE FROM INVENTORY ORDER BY PROD_NAME; Product Prices Product: Product Product Number Name Price Adapter $ Adapter $ Adapter $ CD Player $89.87 $ CD System $ $ CD System $ Product: CD System 10 Product Prices Product: CD System 11 Product Product Number Name Price CD System $ CD System $ $ For more examples, see TTITLE UniData SQL Commands Reference

31 CLEAR Syntax CLEAR {BREAK COLUMN COMPUTE} Description The CLEAR command erases the current definition for the specified option. Parameters The following table describes each parameter of the syntax. Parameter BREAK COLUMN COMPUTE Description Clears the break definition specified by the BREAK command. Clears column definitions defined by the COLUMN command. Clears computation definitions set by COMPUTE commands. CLEAR Parameters Example sql> CLEAR COMPUTE; computes cleared sql> CLEAR BREAK; breaks cleared 1-25

32 COLUMN Syntax COLUMN {attribute_name expression} [ALIAS alias] [CLEAR DEFAULT] [FORMAT column_format] [HEADING "text" [JUSTIFY {LEFT CENTER RIGHT}]] [LIKE {expression attribute_label}] [NEWLINE] [NEW_VALUE new_val] [OLD_VALUE old_val] [NOPRINT PRINT] [NULL "text"] [ON OFF] [SPACE n] [WRAPPED WORD_WRAPPED TRUNCATED] Description The COLUMN command associates display formats for column headings with specified attributes. If more than one COLUMN command is applied to the same attribute, the last overrides all previous settings. Tip: The COLUMN command formats all displayed attributes of the same name in all tables. When selecting columns of the same name from multiple tables, avoid confusion by assigning an attribute label to at least one of them in the SELECT statement that uses the COLUMN setting UniData SQL Commands Reference

33 Parameters The following table describes each parameter of the syntax. Parameter attribute_name expression ALIAS alias CLEAR DEFAULT FORMAT column_format HEADING "text" JUSTIFY LIKE expression LIKE attribute_label Description Specifies the attribute to format. Any combination of attribute names, constants, arithmetic operators, and UniData SQL functions that together select attributes to be associated with display formats. Expressions that contain spaces must be enclosed in quotation marks. expression must be defined the same way as in the SELECT statement. Keywords must be entered uppercase even if they were lowercase in the SELECT statement. Assigns an alias to expression or attribute_spec. You may use this alias in expression or attribute_spec anywhere in the statement; however, alias must be defined for each statement. Removes the column definition for expression or attribute_spec. Resets the column definition to default settings, including PRINT ON and WRAP ON. Formats values displayed in this column. For information on these options, see column_format Options following this table. Assigns a column heading. The default column heading is the attribute name or the expression itself. Enclose text within quotation marks if it contains spaces or special characters. If the text contains HEADSEP, the column heading is displayed over multiple lines. Aligns the column heading. HEADING must be specified to use JUSTIFY. LEFT Left-align column heading. CENTER Center column heading. RIGHT Align column heading at right column margin. Copies the COLUMN specification of another column, or as defined in expression. LIKE attribute_label copies the display name of an attribute. COLUMN Parameters 1-27

34 Parameter NEWLINE NEW_VALUE new_val NOPRINT PRINT NULL "text" OFF ON OLD_VALUE old_val SPACE n WRAPPED WORD_WRAPPED TRUNCATED no option Description With SET WRAP HORI, starts a new line before displaying the value of a column. With SET WRAP DEF, switches to vertical format. Saves the current value of an attribute for use in TTITLE statements to print a header that reflects current attribute values. Turns on or off printing column text. The default is PRINT. With null value handling on, the text variable specifies text to be displayed for the null value. This text overrides the default text specified in the NULL clause of the SET command, if any. If you do not specify text for the null value in either the COLUMN command or the SET command, the null value is represented by an empty string. With null value handling off, this keyword has no effect. Turns COLUMN settings off or on without affecting the settings. The default is ON. Saves the current value of an attribute for use in BTITLE statements to print a footer that reflects current attribute values. Places the next column n spaces to the right of the current position. Defaults to the position established by the SET command (SET SPACE n). Specifies wrapping or truncating of column text when text is wider than the column. WRAPPED wraps text to the next line; default. WORD_WRAPPED wraps text without breaking words. TRUNCATED deletes text that does not fit in the column. Displays current column definitions. COLUMN Parameters (continued) column_format Options column_format specifies the display format for values in the column. column_format must be enclosed in quotation marks, and can be one of the following: 1-28 UniData SQL Commands Reference

35 Character Format Options The format for a character string is An where n is the column width. The default is the length specified in the dictionary definition of the attribute. Date Format Options You cannot specify format options for date attributes; the formatting specified in the dictionary definition of the attribute is used. Numeric Format Options Use the options in the following table to build a display mask for formatting numeric values. Option Explanation Example of Mask 9 Represents one numeric display position Display leading zeros $ Prefix a dollar sign before the displayed value. $9999 B Print leading zeros as blank. B999 MI Display minus sign (-) after a negative value. 9999MI PR Display a negative value in angle brackets 9999PR. Align on the decimal point , Insert a comma where placed in the mask. 99,999 V EEEE Multiply the value by the n power of 10, where n is the number of 9s after V. Display the scientific notation (the format must contain four Es). column_format Numeric Options 999V EEEE Examples The following COLUMN statement skips a line after ORD_TIME is displayed, and presents the data in vertical format: sql> COLUMN ORD_TIME NEWLINE; 1-29

36 The following output is produced when you select ORD_TIME after executing the above COLUMN command: sql> SELECT ORD_DATE, ORD_TIME FROM ORDERS; Page 1 Order Date 01/13/1996 Order Time 12:30PM Order Date 09/28/1995 Order Time 04:34PM Order Date 01/14/1996 Order Time 03:00PM... Enter <New line> to continue...q Next, we clear the COLUMN setting and execute the same SELECT statement: sql> CLEAR COLUMN; columns cleared sql> SELECT ORD_DATE, ORD_TIME FROM ORDERS; The same attributes are displayed as in the preceding example, but no lines are skipped: Page 1 Order Order Date Time /13/ :30PM 09/28/ :34PM 01/14/ :00PM 10/05/ :11AM 01/24/ :09PM 01/15/ :00AM 12/04/ :45AM 01/24/ :27PM 12/13/ :51PM... Enter <New line> to continue...q 1-30 UniData SQL Commands Reference

37 COMMIT Syntax COMMIT [WORK] Description The UniData SQL COMMIT command concludes an active transaction. The optional keyword WORK is provided for backward compatibility. If a COMMIT command executes without an active transaction, UniData SQL displays the following error message: Invalid transaction termination: no active transaction. The system performs the following steps during a transaction commit: Disables the break key. Writes all updates. Releases all locks acquired within the transaction. Enables the break key. If the transaction cannot commit, the system performs the following steps: Aborts the transaction. Releases all locks acquired within the transaction. 1-31

38 UniBasic STATUS Function Return Values The UniBasic STATUS function returns the values in the following table if executed immediately after the UniData SQL COMMIT command. Value Description 0 The commit completed successfully. 1 Transaction not started. 3 Transaction cannot commit. UniBasic STATUS Return Values 1-32 UniData SQL Commands Reference

39 COMO Syntax COMO option filename Description The COMO command saves the history of a user session. When you open a COMO file, UniData SQL stores all terminal input and output in the UniData SQL DIR-type table, _PH_, in the file O_filename (O_filename is a UNIX sequential file). To specify a COMO file name that is not SQL compliant, enclose the file name in quotation marks, as shown in the following statement: COMO ON file.name. Tip: COMO files grow very quickly. IBM recommends that you periodically review and delete unused COMO files. option Values The following options are valid for use with COMO. Option ON OFF SPOOL DELETE LIST APPEND Description Opens a new COMO output file. If filename exists, contents are overwritten. Closes the COMO file and stops capturing terminal display. Sends a copy of a selected COMO file to the printer. Deletes the specified COMO file from the _PH_ table. Lists all the COMO files in the _PH_ table. Appends terminal display to an existing COMO file. COMO Options 1-33

40 Examples Note: The following examples show the COMO file name as it appears in UniData for UNIX. If you are using UniData for Windows Platforms, you would see the full path for the COMO file (such as D:\UniData72\demo\_PH_\O_SAVESQL). The following example demonstrates creating a COMO file, executing a command, and closing the COMO file: sql> COMO ON SAVESQL; /usr/ud72/_ph_/o_savesql established sql> SELECT * FROM INVENTORY; Page 1 INVENTORY Inventory Date 01/09/1996 Inventory Time 08:00AM Product Name Photocopier Features Personal Photocopier Color Quanti Price Reorde Beige 785 $ INVENTORY Inventory Date 01/11/1996 Inventory Time 12:00PM Product Name Trackball Features Super Deluxe Model Color Quanti Price Reorde Gray 494 $ INVENTORY Inventory Date 12/15/1995 Inventory Time 05:34PM Product Name Scanner Enter <New line> to continue...q sql> COMO OFF SAVESQL; _PH_/O_SAVESQL closed 1-34 UniData SQL Commands Reference

41 The next example shows the contents of the COMO file SAVESQL. /usr/ud72/_ph_/o_savesql established sql> SELECT * FROM INVENTORY; Page 1 INVENTORY Inventory Date 01/09/1996 Inventory Time 08:00AM Product Name Photocopier Features Personal Photocopier Color Quanti Price Reorde Beige 785 $ INVENTORY Inventory Date 01/11/1996 Inventory Time 12:00PM Product Name Trackball Features Super Deluxe Model Color Quanti Price Reorde Gray 494 $ INVENTORY Inventory Date 12/15/1995 Inventory Time 05:34PM Product Name Scanner Enter <New line> to continue...q sql> COMO OFF SAVESQL; 1-35

42 COMPUTE Syntax COMPUTE {AVG COUNT MAX MIN NUMBER STD SUM VARIANCE...} OF {expression attribute_name}... ON {expression attribute_ name REPORT ROW...} Description The COMPUTE command performs computations on groups of data selected by a SELECT statement. You may apply multiple COMPUTE commands to the same column. To activate options set with COMPUTE, you must subsequently execute the BREAK command and specify the same ON condition as in the COMPUTE statement. You must also display the BREAK attribute for COMPUTE to take effect. When the break (change in data value) occurs, UniData SQL performs the calculations specified by the COMPUTE statement. Tip: Use ORDER BY in the SELECT statement that uses the COMPUTE settings to order the rows in the correct sequence. Parameters The following table describes each parameter of the syntax. Parameter AVG COUNT MAX MIN Description Computes the average value. Valid for numeric data. Counts the number of values in a row. Valid for all data types. UniData SQL does not count the null value. Finds the largest value. Valid for numeric and character type data. Finds the smallest value. Valid for numeric and character type data. COMPUTE Parameters 1-36 UniData SQL Commands Reference

43 Parameter NUMBER STD SUM VARIANCE OF expression attribute_name ON expression attribute_name REPORT ROW Description Counts the number of records in a table. Valid for all data types and the null value. Computes the standard deviation. Valid for numeric data. Computes the sum of the values. Valid for numeric data. Computes the variance. Valid for numeric data. Specifies expression or attribute_name to use in computations. Settings made in the COMPUTE statement execute when you select this specified attribute or expression in subsequent SELECT statements. To perform computations using an attribute without printing the result, execute the NOPRINT option in the COLUMN command against that attribute_name. Specifies expression or attribute_name to compute on. For a computation and break to occur on an attribute, you must also specify attribute_name in a BREAK command. When the break (change in data value) occurs, UniData SQL executes COMPUTE command computations. Prints the result of computations at the end of the report. Prints the result of computations and restart the computation for each row. COMPUTE Parameters (continued) 1-37

44 Examples The following example demonstrates the use of COMPUTE to obtain the average price of all items in the ORDERS file: sql> COMPUTE AVG OF PRICE ON REPORT; sql> BREAK ON PRICE ON REPORT; sql> SELECT PRICE FROM ORDERS; Page 1 Price $ $1, $1, $ $ $29.97 $48.82 $34.97 $8.99 $ $ The next example demonstrates using the COMPUTE command to obtain daily sales totals: sql> BREAK ON ORD_DATE SKIP 1; sql> COLUMN ORD_DATE HEADING "Order Placed On:" JUSTIFY CENTER; sql> COMPUTE SUM OF PRICE ON ORD_DATE; sql> SELECT CLIENT_NO, PRODUCT_NO, QTY, PRICE FROM ORDERS sql> ORDER BY ORD_DATE; The final example shows a partial listing of the output produced by these statements: Page 1 Order Client Placed On: ORDERS Number Product Nu Qty Price /01/ $ $ $ $ $29.97 ********** sum $ UniData SQL Commands Reference

45 04/09/ $2, ********** sum $2,

46 CREATE INDEX Syntax CREATE INDEX index_name ON table_name (attribute_name) Description The UniData SQL CREATE INDEX command creates an alternate key index on attribute_name in the table specified by table_name. The UniData SQL CREATE INDEX command also builds the index with data from the table being indexed. Note: The UniData SQL CREATE INDEX command performs the functions of both ECL commands CREATE.INDEX and BUILD.INDEX. The greater the number of records, the more an index reduces access time. In a table containing a large number of records, an index significantly reduces the amount of time required for a SELECT to display data (providing the SELECT statement has a search condition that takes advantage of the index). The alternate key attribute, designated by attribute_name, may be any D-type singlevalued or multivalued attribute, virtual attribute, or may be a phrase that contains only one attribute. For indexes based on virtual attributes, index_name must be the same as attribute_name. You can create indexes on different attributes in one data table; however, you cannot create more than one index on a single attribute. When you create the first index for a table, UniData SQL prompts you to enter a length for the alternate key. Note: CREATE INDEX does not check the data for duplicate records. To check for duplicate records when creating an index, use the ECL command CREATE.INDEX. Allocate a length that will accommodate the longest value in all attributes to be indexed. An adequate key length makes the index efficient but does not prevent it from accepting longer values. Maximum key length is 1020 plus the number you assign. The default key length is UniData SQL Commands Reference

47 Examples The following example demonstrate creating an alternate key index for the INVENTORY table on the attribute PROD_NAME. The new index is named PROD_IDX. Because this is the first index to be created on INVENTORY, the user is prompted for alternate key length. sql> CREATE INDEX PROD_IDX ON INVENTORY (PROD_NAME); Alternate key length (default 20): 50 "PRODUCT" created One "*" represents 1000 records Building "PROD_IDX" record(s) processed. The next example demonstrates creating an index, then using it to decrease the length of time required to access data when a SELECT is performed on the indexed field. Without an index on CLIENT_NO, the same SELECT statement might take several times longer to retrieve the data. sql> CREATE INDEX CLIENT_ORDS ON ORDERS(CLIENT_NO); "CLIENT_ORDS" created One "*" represents 1000 records Building "CLIENT_ORDS" record(s) processed. sql> SELECT CLIENT_NO, ID, PRODUCT_NO, QTY FROM ORDERS sql> WHERE CLIENT_NO = "10004"; Page 1 Client Number ORDERS Product Nu Qty records listed 1-41

48 CREATE SUBTABLE Syntax CREATE SUBTABLE subtable_name [(attribute_subtable_name [,attribute_subtable_name]...)] AS SELECT query_spec [PRIMARY KEY attribute_name[,attribute_name]...] [FOREIGN KEY attribute_name[,attribute_name]... REFERENCES subtable_name] Description The CREATE SUBTABLE command creates a UniData SQL view that presents values from the base table in such a way that those values can be viewed and updated using 1NF ANSI-standard SQL Data Manipulation Language (DML) commands. This enables you to update data in UniData SQL base tables using desktop tools that access these subtables through UniData ODBC. Representing Multivalues and Multi-Subvalues You must unnest multivalued and multi-subvalued attributes in the SELECT clause that is a part of the CREATE SUBTABLE statement. If you do not, the system displays an error message and does not create the subtable. Subtable Requirements To represent the three nested levels of data within UniData SQL tables (singlevalued, multivalued, and multi-subvalued), you must create three subtables: one for each nested level. The nested levels are referred to as NL0, NL1, and NL2. NL0 subtable represents singlevalued attributes. NL1 subtable represents multivalued attributes. All multivalued attributes must be in the same association. NL2 subtable represents multi-subvalued attributes. All multi-subvalued attributes must be in the same association UniData SQL Commands Reference

49 These subtables are linked through primary and foreign keys. Note: You cannot create a single subtable that contains attributes from different associations or that combine more than one value type such as combining multivalued and multi-subvalued attributes. If you do, UniData returns an error message indicating the type of error, such as: a subtable cannot contain both MV and MS attributes. (Note that the foreign key, which is the primary key of the subtable or table at the next-higher level, is the only exception to this rule.) Primary and Foreign Keys The NL0 subtable defines the primary key. The purpose of a primary key is to specify one or more attributes whose data values are unique among all values for that record. UniData SQL does not allow a record to be added to a subtable with a duplicate key value. The primary key of the NL0 subtable becomes the foreign key in the NL1 subtable. To enable UniData SQL to locate the primary key, you name the NL0 subtable in the REFERENCES clause of the CREATE SUBTABLE statement that creates the NL1 subtable. To create an NL2 subtable, use the NL1 subtable s primary key as the NL2 table s foreign key, and list the NL1 subtable name in the REFERENCES clause. No primary key is required when you create an NL2 subtable, because no lower-level subtable will reference this (NL2) subtable. However, you may want to define a primary key for NL2 subtables to ensure the uniqueness of the data. The primary and foreign keys accomplish the same data relationships in subtables as associations do in UniData SQL base tables. The following table summarizes the number and value type of attributes required to create primary and foreign keys in subtables. Key Subtable Type NL0 NL1 NL2 Primary 1 S 1 S, 1 MV 1 S, 1 MV, 1 MS Foreign n/a 1 S 1 S, 1 MV Primary and Foreign Keys for Subtables 1-43

50 Note: If you create an NL1 subtable without a primary key and later decide you want to create an NL2 subtable, you must drop the NL1 subtable and create an NL1 subtable with a primary key. After this, you can create an NL2 subtable that references the primary key in the NL1 subtable. Unique and Generated Keys You create one of the following types of primary or foreign keys for each subtable: Unique keys, in which the uniqueness of the key value depends on the data itself. In this case, actual attribute names are used in the PRIMARY KEY or FOREIGN KEY clauses. Generated keys, in which UniData SQL assigns a number to be part of each key value, so that the key value is unique even when the data itself is not. In this case, use NL1_KEY or NL2_KEY in the SELECT statement, rename the selected values, and use these new names in the PRIMARY KEY or FOREIGN KEY clause. The concept of unique and generated keys applies to both primary and foreign keys, because the foreign key of the referencing subtable is the primary key of the referenced subtable UniData SQL Commands Reference

51 Parameters The following table describes each parameter of the syntax. Parameter subtable_name attribute_subtable_name AS SELECT query_spec PRIMARY KEY attribute_name FOREIGN KEY attribute_name REFERENCES subtable_name Description Specifies the name of the new subtable. Subtable names can contain alphabetic characters, numbers, or the underscore character. ODBC prohibits the use of other special characters. The following restrictions apply to subtable names: The first character of the name cannot be a number. The subtable name must be unique among tables, subtables, and views in the database. The maximum length of a subtable name is 30 characters. The name to be used for the attribute in this subtable. If you rename one attribute, you must list all attributes, even if you use the attribute name from the base table. You must rename attributes when an expression is included in query_spec. Selects data to include in the subtable. query_spec is defined in the SELECT statement section of this manual. You must unnest nested attributes to create a subtable through which you can update the base table. The SELECT clause cannot contain more than 255 virtual attributes. One or more attributes to use as the primary key for this subtable. If you rename an attribute (see the preceding description for attribute_subtable_name), you must use the new name here. One or more attributes to use as the foreign key for this subtable. The foreign key refers to the primary key of a subtable one nested level higher. If you rename an attribute (see renamed_attribute, above), you must use the new name here. The corresponding subtable name, one nested level higher. The subtable name contains, as a primary key, the attribute_names listed in the FOREIGN KEY clause of this statement. CREATE SUBTABLE Parameters 1-45