Chapter 8 Access Database

Transcription

1 Chapter 8 Access Database Content Define ODBC data source Create Table Template Create Bind List Operate Database Summary In this chapter we would tell how to record and query the data to database. We use Access database to record data, time, description of valve, condition of valve. We use SQL in Kingscada3.0 to achieve it. The KingSCADA SQL access function is used for transferring data between KingSCADA and other ODBC databases. KingSCADA contains the SQL access manager and SQL functions KingSCADA SQL access manager creates a connection between database columns and KingSCADA tags. It contains a table template and bind list. Create tables in the database by using table templates. Build a connection between database fields and KingSCADA s variables by using the bind list. Data in database can also be manipulated through SQL functions. Section 1 Define ODBC data source and database. Step 1: Create a new database (filename: mydb.mdb). Step 2: In the control Panel of windows, double click the data source (ODBC) option. The ODBC Data source administrator will appears, shown in figure 8-1. Figure 8-1 ODBC data source

2 Section 2 Create table template and bind list Create table template To create a table template, the process is described as below: Step 1: Select the SQL access manager in the tree structure of KingSCADA project development environment and then click table template item and the new button in the right hand side edit area to open the table template window, shown below: Figure 8-2 Create table template The data type of the four fields is all string. Step 2: Click the OK button to finish creating the table template. Creating table template is to definite format of database, we could create table in Access database automatically by using SQLCreatTable() function. If we just need to create table once in database, we could create a table in database. Don t need to create the table template. Create bind list Before creating bind list, we need create two string variable: 阀 门 描 述 description of valve, 阀 门 状 态 condition of valve. To create a list follow the steps described below. Step 1: Select the SQL access manager in tree directory of the KingSCADA project development environment and select bind list, then item and click the new button in right hand side edit area to open the band list window.

3 Figure 8-3 Create bind list The relation between fields and tags is as following. Access database table tags fields data \\local\$date Time \\local\$time Description of valve \\local\ 阀 门 描 述 Condition of valve \\local\ 阀 门 状 态 PS: record \\local\$date into data field in Access database, etc. Step 2: Click OK to finish creating the bind list. Section 3 Operate database 1. Connect database Step 1: Create a new memory integer variable in tag dictionary of KingSCADA. Variable Name: DeviceID Variable Type: Memory integer Step 2: Create a picture named database operation picture and add a button with the text property set as database connection. Input a section of script in the button s LeftMouseDown event, shown in Figure 8-4:

4 Figure 8-4 Connect database scripts The above script function is used to build a connection between KingSCADA and the kingview database (connection to the database.mdb). In practical projects, the above script is written in the project development environment by selecting script, system script, application script and finally clicking on OnApplicationStartup. The system will automatically connect to the database when system starts. 2. Disconnect database Draw a button in picture, configure properties as below: Button text: disconnect database. Mouse trigger leftup animation link as below: Figure 8-5 Disconnect database scripts 3. Create database table Add a button with the text property of create database table in the database operation picture. Input a section of script in the button s LeftMouseDown event, shown in Figure 8-6:

5 Figure 8-6 Create database table script 4. Insert record A button can be created with the text property to insert a record in the database operation picture. Input a section of script in the button s LeftMouseDown event as shown in Figure 8-7: Figure 8-7 Insert record script When \\local\activator.valve_gate changes, a record would be inserted in table. 5. query records Records can be queried in the database through SQLFirst, SQLNext, SQLPrev and SQLLast functions. These functions are described below. Step 1: To show the database data in a KingSCADA picture, a bind list has to be created. Its field name is consistent with table and field names in the database. Variable types are connected with field types in database. Three memory variables in tag dictionary can be defined in the project development environment. 1. Variable Name: 记 录 日 期 2. Variable Name: 记 录 时 间

6 3. Variable Name: 阀 门 描 述 1 4. Variable Name: 阀 门 状 态 1 Step 2: Create a new picture named database query picture and add four text-boxes to it. Separately connect the variables \\local \ 记 录 日 期 (record date), \\local\ 记 录 时 间 (record time), \\local \ 阀 门 描 述 1 and \\local \ 阀 门 状 态 1 in text-box s string output and analogue output. Querying results will be shown in text-boxes. Step 3: Create a bind list in the project development environment. The bind list properties window is shown below: Figure 8-8 bind list properties Step 4: Add a button with the text property set as get selecting sets in the picture. Input the section of script in the LeftMouseDown event, shown in Figure 8-9:

7 Figure 8-9 query records scripts The above script function returns the first record of database table named KingTable according to the Bind2 format Step 5: Add four buttons to the picture. Set the properties shown as below: 1. Button text:the First record Script: SQLFirst( DeviceID ); 2. Button text:next record Script: SQLNext( DeviceID ); 3. Button text:previous record Script: SQLPrev ( DeviceID ); 4. Button text:last record Script: SQLLast ( DeviceID ); The first, next, previous and last records cab be queried from database by using the above scripts. After-school practice: 1. Use the other SQL functions in KingScada Record conditions of valve and water pump in database.