Jincang database kingbasees client programming interface guide ODBC (5. Development process)

5.  The development process

In the correct setting KingbaseES ODBC After the data source , Application usage KingbaseES ODBC API The steps are as follows ：

1. call SQLAllocHandle Function allocation environment handle .

2. call SQLAllocHandle Function to allocate connection handle .

3. Use the allocated connection handle to call SQLConnect,SQLBrowseConnect perhaps SQLDriverConnect connect to a data source . It specifies the name of the data source and any additional information needed to complete the connection .

4. Process one or more SQL sentence ：

   The application will SQL Put the text string in the buffer .

   If the statement includes parameter markers , Then set it to the parameter value .

   If the statement returns a result set , The application program assigns the tag name to the statement or uses the default tag name of the driver . The application is “SQLPrepare or SQLExecute” Submit statement .

   If the statement creates a result set , The application asks for the result set attribute , For example, the number of columns , And the name of a specific column 、 Type, etc . It allocates storage for each column in the result set and retrieves the results .

   If the statement causes an error , The application program extracts the error information from the driver and takes corresponding actions .

5. End each transaction by committing or re operating .

6. When the interaction between the application and the data source ends , Terminate connection , Release the corresponding handle . The sequence of function execution is as follows ：

   1. SQLAllocHandle（SQL_HANDLE_ENV,NULL,&henv）<=> SQLAllocEnv ;

   2. SQLAllocHandle（SQL_HANDLE_DBC,henv,&hdbc）<=> SQLAllocConnect ;

   3. SQLConnect ;

   4. SQLAllocHandle（SQL_HANDLE_STMT,hdbc,&hstmt）<=> SQLAllocStmt ;

   5. Handle SQL sentence (SQLPrepare This step can be omitted, but it must be called SQLExecDirect);

   6. If there are binding parameters, the binding assignment （SQLBindParameter）;

   7. Can pass SQLGetDescField, SQLColAttribute, SQLDescribeCol Wait for functions to get information （ It can be omitted ）;

   8. adopt SQLExecute or SQLExecDirect Execute function ;

   9. To get the results (SQLFetch, SQLBindCol, SQLGetData...);

   10. SQLFreeHandle（SQL_HANDLE_STMT,hstmt）<=> SQLFreeStmt ;

   11. SQLDisconnect ;

   12. SQLFreeHandle（SQL_HANDLE_DBC,hdbc）<=> SQLFreeConnect ;

   13. SQLFreeHandle（SQL_HANDLE_ENV,henv）<=> SQLFreeEnv ;

In order for users to better use KingbaseES ODBC Function access KingbaseES database , This document also gives some ODBC Operation example of , Please see the   example  .