ODBC Overview and Information

Transcription

1 Appendix A ODBC ODBC Overview and Information ODBC, (Open Database Connectivity), is Microsoft s strategic interface for accessing data in an environment of relational and non-relational database management systems (DBMS s). ODBC allows applications to access multiple data sources without having to understand the underlying format of the data being read. It is through this mechanism that the Loftware system is able to access your data. The standard Loftware setup program installs Microsoft Data Access Components (MDAC) which includes the following ODBC drivers: Microsoft Access, dbase, Microsoft Excel, Microsoft FoxPRO, Paradox, Text (CSV and Fixed Length), SQL Server, and Oracle. No 16-bit drivers are included. If your data is in a different format, such as DB2, Sybase, Btrieve etc., you must obtain a 32-bit ODBC driver that is compliant with your database. You can often find these drivers by contacting your provider or by searching on the Internet. ODBC manages databases through the use of registered data sources. A data source consists of a specific set of data (e.g. a database), the information required to access that data, and the location of the data source. Examples of Data Sources 1. A directory containing a set of dbase files you want to access. 2. An SQL Server database, the server on which it resides and the network used to access that server. 3. A Microsoft Access database 4. An Oracle database through a gateway to a Vax or AS/400 Connecting to a data source means establishing communications with a DBMS in order to access that data source s data. When you connect to a data source from an application through an ODBC driver, the driver makes the connection for you, either locally or across a network. How Loftware Label Manager Uses ODBC All databases are accessed using ODBC in Loftware Label Manager. The advantage of this is that Loftware Label Manager connects to any data source for which there is an ODBC driver. Note: If you are using the Loftware Print Server (LPS), data from your database is usually 'pushed' to the LPS. Refer to the section entitled 'The Concept of Data Push' in Chapter 1 of the LPS User s Guide. User's Guide Loftware Label Manager Appendix A ODBC 1

2 Before you can use a database as a data source in Loftware Label Manager, you must set up an ODBC data source for the data. The Loftware setup program creates 4 sample data sources for you, each of which points to sample databases in the 'Program Files\Loftware Labeling\dbases' directory. These datasources can be viewed and changed from the ODBC control panel applet as described below. Loftware dbase Sample Sample Data Source for dbase IV and V files Loftware Access Sample Sample Access database Loftware Excel Sample Sample Excel database Loftware Text Sample Sample ASCII text databases The ODBC Data Source Administrator Access the ODBC control panel applet by clicking Start > Programs > Loftware Labeling > Data Sources (ODBC). All Datasource editing is done from there. There are several different categories of datasources: User, System, and File. These categories are explained in the sections below. Choose the one that best suits your needs and then go to the Adding a Data Source section for information on how to set it up. The Tracing and ODBC drivers tabs are also explained below. Note: The figure below displays the Administrator dialog box after several User Data Sources have been added Figure A-A: ODBC Data Source Administrator Screen 2 Appendix A ODBC User's Guide Loftware Label Manager

3 User Data Source Tab (User DSN) Adds, deletes, or sets up data sources with User DSNs. (DSN = Data Source Name) These data source configurations are local to a computer, and may only be used by the current user. Note: A networked database can be accessed with a User DSN. User Data Sources List A list of all user DSNs that includes the name of each DSN and the driver associated with the DSN. double-clicking auserdsndisplaysthedriver-specificdatasourcesetupdialogbox. Configure Displays the driver-specific data source setup dialog box that enables you to change the configuration of an existing user data source. You must select the name of a user data source from the list before choosing the Configure button. Add Adds a new user data source. If you choose this button, the Create New Data Source dialog box is displayed with a list of drivers. Choose the driver for which you are adding a user data source. After you choose Finish, a driver-specific setup dialog box is displayed. Remove Removes an existing user data source. You must select the name of the user data source you want to remove from the list before choosing the Remove button. OK Closes the Administrator dialog box. OK does not have to be pressed to accept changes to the User Data Sources list. Changes to the list have already been accepted once the OK button in the data source setup dialog box has been pressed. Cancel Closes the Administrator dialog box. Note that changes to the User Data Sources list are not rejected if the Cancel button is pushed. Help Displays the Microsoft ODBC Help screen. System Data Source Tab (System DSN) Adds, deletes, or sets up data sources with system DSNs. These data source configurations are local to a computer, but are not dedicated to a user. The system, or any user having privileges, can use a data source set up with a system DSN. Note: A networked database can be accessed with a System DSN. User's Guide Loftware Label Manager Appendix A ODBC 3

4 System Data Sources List A list of all system DSNs that includes the name of each DSN and the driver associated with the DSN. Double-clicking a system DSN displays the driver-specific data source setup dialog box. Configure Displays the driver-specific data source setup dialog box that enables you to change the configuration of an existing system data source. You must select the name of a system data source from the list before choosing the Configure button. Add Adds a new system data source. If you choose this button, the Create New Data Source dialog box is displayed with a list of drivers. Choose the driver for which you are adding a system data source. After you choose Finish, a driver-specific setup dialog box is displayed. Remove Removes an existing system data source. You must select the name of the system data source you want to remove from the list before choosing the Remove button. OK Closes the Administrator dialog box. OK does not have to be pressed to accept changes to the System Data Sources list. Changes to the list have already been accepted once the OK button in the data source setup dialog box has been pressed. Cancel Closes the Administrator dialog box. Note that changes to the User Data Sources list are not rejected if the Cancel button is pushed. Help Displays the Microsoft ODBC Help screen. File Data Source Tab (File DSN) Note: Loftware Label Manager does not support File DSNs. Use System and User DSNs. ODBC Drivers Tab Displays information about the installed ODBC drivers. The ODBC Drivers list shows you which drivers are already installed on your computer. ODBC Drivers List Displays the name, version, company, file name, and file creation date of each ODBC driver installed on the computer. OK Closes the Administrator dialog box. 4 Appendix A ODBC User's Guide Loftware Label Manager

5 Cancel Closes the Administrator dialog box. Note that this dialog box does not include the functions to Add or Delete. An ODBC driver must be added or deleted through the driver s setup program. Tracing Tab Enables you to specify how the ODBC Driver Manager traces calls to ODBC functions. The Driver Manager can trace calls all of the time, for one connection only; dynamically; or can allow tracing to be performed by a custom trace DLL. Note: Tracing is typically only used for troubleshooting ODBC connections. Most Loftware Label Manager users do not need to enable tracing. When to Trace Enables tracing and determines when tracing is initiated. These controls can only be set while there is no connection. If Don t trace is selected, tracing is disabled. If All the time is selected, tracing is automatically performed at all times, for all connections on the machine. If One-time only is selected, tracing is performed only for the next connection, and is disabled after that connection is disconnected. Start Tracing Now Enables dynamic tracing that is performed as long as the ODBC Administrator dialog box is displayed. Dynamic tracing can be enabled whether a connection has been made or not. After it is clicked, the Start Tracing Now button is replaced by a Stop Tracing Now button. When the Stop Tracing Now button is clicked, or the ODBC Administrator dialog box is closed, dynamic tracing is disabled. Log file path Displays the path and file name for the file that stores the tracing information. The default path and file name (sql.log) are taken from the system information, but a new file is specified by either entering a new path and file name, or choosing the Browse button and selecting a directory and file. Browse Allows you to select the path and file name for the log file by browsing machine directories. Custom Trace DLL This control allows the user to select a trace DLL other than odbctrac.dll to perform tracing. The odbctrac.dll file that is shipped with the ODBC SDK can be replaced by a custom DLL of the user s choice. Enter the path and file name of the custom DLL, or CLICK the Custom Trace button to browse the directories for the custom DLL. Custom Trace Allows the user to browse the directory structure for a custom trace DLL. When a DLL has been chosen, the path and file name of the DLL are entered in the Custom Trace DLL text box. OK Accepts changes to tracing and closes the Administrator dialog box. User's Guide Loftware Label Manager Appendix A ODBC 5

6 Cancel Closes the Administrator dialog box without accepting changes to tracing. Apply Accepts any changes that have been made to tracing without closing the Administrator dialog box. The Apply button is grayed if no changes have been made. Working with Data Sources Adding a Data Source 1. Choose Start > Programs > Loftware Labeling > Data Sources (ODBC). 2. Choose the Add button in the Data Sources dialog box 3. Select the driver s name from the installed ODBC Drivers list in the Add Data Source dialog box and click OK. (If the driver for the Data Source you are trying to add is not there, go back to the ODBC installation program and install it.) 4. Enter information to set up the data source in the ODBC Setup dialog box. (Note that the Description entry is optional and cannot exceed 79 characters.) Adding a System Data Source A data source can be set up with a system data-source name (DSN) that can be used by more than one user on the same machine. The system DSN can also be used by a system-wide service, which can then gain access to the data source even if no user is logged onto the machine. 1. Choose Start > Programs > Loftware Labeling > Data Sources (ODBC). 2. Choose the System DSN button in the Data Sources dialog box 3. Click the Add button in the System Data Sources dialog box. 4. Select the driver s name from the installed ODBC Drivers list in the Add Data Source dialog box and click OK. 5. Enter information to set up the data source in the ODBC Setup dialog box; click OK (Note that the Description entry cannot exceed 79 characters) Modifying a Data Source 1. Choose Start > Programs > Loftware Labeling > Data Sources (ODBC). 2. Select the data source from the Data Sources list in the Data Sources dialog box 3. Choose the Setup button. 6 Appendix A ODBC User's Guide Loftware Label Manager

7 4. Enter information to set up the data source in the ODBC Setup dialog box. (Note that the Description entry is optional and cannot exceed 79 characters). Deleting a Data Source 1. Choose Start > Program Files > Loftware Labeling > Data Sources (ODBC). 2. Select the data source from the Data Sources list in the Data Sources dialog box. 3. CLICK the remove button, and then CLICK the Yes button to confirm the deletion. Data Source Conversion The 32-bit data sources used with the ODBC Desktop Database Drivers version 2.0 are automatically converted to new 32-bit data sources for version 3.5 drivers. No conversion is provided for 16-bit data sources. To change a 16-bit data source to a 32-bit data source, create a new 32-bit data source, and then (optionally) delete the old 16-bit data source. A 32-bit data source and a 16-bit data source cannot share the same name. Hints and Troubleshooting ODBC If you are moving your label from one PC to another, and it is connected to an ODBC datasource, make sure that the PC you are moving to has the exact same datasource name in the ODBC Control Panel. If you are unsure of what datasource name was used, you may double click a field on your label that is connected to a database in design mode. The datasource name, table and field are reported. Datasource names are not case sensitive. Be aware of illegal and reserved datasource names. Stay away from names like Table, Field, Database, Text, etc. Do not include special characters like \, Fields that have been defined to be Number in your database may be reported by ODBC in scientific notation. Use Text or Character fields whenever possible. This is a common occurrence when connecting to an Excel spreadsheet. If you need to pass high ASCII characters in your data, your best chance for success is using the Microsoft Text ODBC driver on a CSV or Fixed length text database. If you get a Type Mismatch error when retrieving data, it means that the field column type in the database has changed since the connection was made. Reconnect the associated field on your label. Do not have a subdirectory with the same name as your database under the directory in which your database resides. This creates a Couldn t open file unknown message. If using Microsoft Access, make sure that you have checked Read/Design permissions. If they are not checked, you may get a situation where you can see table names but no field names. Avoid using ODBC indexes whenever possible. User's Guide Loftware Label Manager Appendix A ODBC 7

8 When first choosing a datasource, you may get an error message. Continue by pressing either OK or Cancel, and try to connect to your database. Loftware Label Manager always accesses the first DSN by default. If the DSN is not valid, a warning displays. Choose another DSN. The chosen DSN becomes the default DSN after connecting to your database. Records added to the database from an external location while printing from another may not be immediately available to the Loftware print modules. If you are using the Database-Image datasource and you get a message saying that the image is not found, try making the field length property of the image field 12 or more characters. See the Loftware Knowledge Base at for information regarding ODBC, such as error messages, reserved words and more troubleshooting hints. 8 Appendix A ODBC User's Guide Loftware Label Manager