Example: Input and Output Arguments in ODBC
The following example describes the usage of the stored procedures specifying input and output arguments in an ODBC application.
Consider the stored procedure spSample2 defined as follows:
CREATE PROCEDURE spSample2( OUT p1 INTEGER, INOUT p2 INTEGER, IN p3 INTEGER) BEGIN SET p1 = p3; SET p2 = p2 * p3; END;
The arguments can be specified in the following format:
SQLBindParameter(..., 1, SQL_PARAM_INPUT_OUTPUT, ..., SQLINTEGER, ..., ..., AppVar2, sizeof(AppVar2), ...); SQLBindParameter(..., 2, SQL_PARAM_INPUT, ..., SQLINTEGER, ..., ..., AppVar3, sizeof(AppVar3), ...);
where the second argument in SQLBindParameter() is the question mark number ordered sequentially from left to right, starting at 1.
Executing the stored procedure:
{ constchar *request = "CALL spSample2(p1, ?, ?)"; ... ... SQLExecDirect(hstmt, request); ... ... }
Retrieving the output parameter values:
SQLBindCol(..., 1, ..., AppVar1, ..., ...); SQLBindCol(..., 2, ..., AppVar2, ..., ...);
where the second argument in the SQLBindCol() is the parameter number of result data, ordered sequentially left to right, starting at 1.