Help Center/ GaussDB/ Developer Guide(Distributed_V2.0-3.x)/ Application Development Guide/ Development Based on ODBC/ Development Process/ Running SQL Statements
Updated on 2025-03-13 GMT+08:00
View PDF
Share

Running SQL Statements

To help users interact with the database, the ODBC provides APIs for executing SQL statements, as shown in Table 1.

Table 1 API description

Function

API

Set statement attributes.

SQLSetStmtAttr

Prepare an SQL statement for execution.

SQLPrepare

Run a prepared SQL statement.

SQLExecute

Bind the parameter marker of an SQL statement to a buffer.

SQLBindParameter

Run an SQL statement directly.

SQLExecDirect
  • ODBC connects applications to the database and delivers the SQL statements sent by an application to the database. It does not parse the SQL syntax. Therefore, when confidential information (such as a plaintext password) is written into the SQL statement sent by an application, the confidential information is exposed in the driver log.
  • If an execution request (not in a transaction block) received in the database contains multiple statements, the request is packed into a transaction. If one of the statements fails, the entire request will be rolled back.
The following is an example (for details about the complete example, see Obtaining and Processing Data in a Database): 
// Set statement attributes.
SQLSetStmtAttr(V_OD_hstmt, SQL_ATTR_QUERY_TIMEOUT, (SQLPOINTER *)3, 0);

// Allocate a statement handle.
SQLAllocHandle(SQL_HANDLE_STMT, V_OD_hdbc, &V_OD_hstmt);  

// Run an SQL statement directly.
SQLExecDirect(V_OD_hstmt, "drop table IF EXISTS customer_t1", SQL_NTS);
SQLExecDirect(V_OD_hstmt, "CREATE TABLE customer_t1(c_customer_sk INTEGER, c_customer_name VARCHAR(32));", SQL_NTS);
SQLExecDirect(V_OD_hstmt, "insert into customer_t1 values(25, 'li')", SQL_NTS);

// Prepare for execution.
SQLPrepare(V_OD_hstmt, "insert into customer_t1 values(?)", SQL_NTS);

// Add parameters.
SQLBindParameter(V_OD_hstmt,1, SQL_PARAM_INPUT, SQL_C_SLONG, SQL_INTEGER, 0, 0,
			   &value, 0, NULL);

// Run the prepared statement.
SQLExecute(V_OD_hstmt);      SQLExecDirect(V_OD_hstmt, "select c_customer_sk from customer_t1", SQL_NTS);
Parent topic: Development Process