Errors with optimized message transfers

The database server stops execution of subsequent statements when an error occurs in a chained statement. For example, in the following code fragment, the intent is to chain five INSERT statements:

SQLExecDirect(hstmt, "create table tab1 (col1 INTEGER)", SQL_NTS);
/* enable message chaining */
SQLSetStmtOption(hstmt, SQL_INFX_ATTR_OPTMSG, 1);
/* these two INSERT statements execute successfully */
SQLExecDirect(hstmt, "insert into tab1 values (1)", SQL_NTS);
SQLExecDirect(hstmt, "insert into tab1 values (2)", SQL_NTS);
/* this INSERT statement generates an error because the data
* in the VALUES clause is not compatible with the column type */
SQLExecDirect(hstmt, "insert into tab1 values ('a')", SQL_NTS);
/* these two INSERT statements never execute */
SQLExecDirect(hstmt, "insert into tab1 values (3)", SQL_NTS);
SQLExecDirect(hstmt, "insert into tab1 values (4)", SQL_NTS);
/* disable message chaining */
SQLSetStmtOption(hstmt, SQL_INFX_ATTR_OPTMSG, 0);
/* commit work */
rc = SQLEndTran (SQL_HANDLE_DBC, hdbc, SQL_COMMIT);
if (rc != SQL_SUCCESS)

In this example, the following actions occur:

• The driver sends the five INSERT statements and the COMMIT WORK statements to the database server for execution.
• The database inserts col1 values of 1 and 2 into the tab1 table.
• The third INSERT statement generates an error, so the database server does not execute the subsequent INSERT statements or the COMMIT WORK statement.
• The driver flushes the message queue when the queue reaches the SQLEndTran function.
• The SQLEndTran function, which is the last statement in the chained statements, returns the error from the failed INSERT statement.