Modifying Data
The following code examples show how to use data modification statements.
Procedure for Updates
Use SQLExecDirect to execute data manipulation statements and use the SQLRowCount function to obtain the affected rows.
INSERT
To insert updates:
SQLAllocHandle(SQL_HANDLE_ENV, SQL_NULL_HANDLE, &henv);
SQLSetEnvAttr(henv, SQL_ATTR_ODBC_VERSION, (void*)SQL_OV_ODBC3, 0);
SQLAllocHandle(SQL_HANDLE_DBC, henv, &hdbc);
SQLDriverConnect(hdbc, 0, (SQLCHAR*)"Dsn=CData Square Source;", SQL_NTS, 0, 0, 0, 0);
SQLExecDirect(hstmt, (SQLCHAR*)"INSERT INTO Payments (DeviceName) VALUES ('Front of store')", SQL_NTS);
SQLINTEGER rowCount = 0;
SQLRowCount(hstmt, &rowCount);
UPDATE
To retrieve updates:
SQLAllocHandle(SQL_HANDLE_ENV, SQL_NULL_HANDLE, &henv);
SQLSetEnvAttr(henv, SQL_ATTR_ODBC_VERSION, (void*)SQL_OV_ODBC3, 0);
SQLAllocHandle(SQL_HANDLE_DBC, henv, &hdbc);
SQLDriverConnect(hdbc, 0, (SQLCHAR*)"Dsn=CData Square Source;", SQL_NTS, 0, 0, 0, 0);
SQLExecDirect(hstmt, (SQLCHAR*)"UPDATE Payments SET DeviceName='Front of store' WHERE Id='Jq74mCczmFXk1tC10GB')", SQL_NTS);
SQLINTEGER rowCount = 0;
SQLRowCount(hstmt, &rowCount);
DELETE
To delete updates:
SQLAllocHandle(SQL_HANDLE_ENV, SQL_NULL_HANDLE, &henv);
SQLSetEnvAttr(henv, SQL_ATTR_ODBC_VERSION, (void*)SQL_OV_ODBC3, 0);
SQLAllocHandle(SQL_HANDLE_DBC, henv, &hdbc);
SQLDriverConnect(hdbc, 0, (SQLCHAR*)"Dsn=CData Square Source;", SQL_NTS, 0, 0, 0, 0);
SQLExecDirect(hstmt, (SQLCHAR*)"DELETE FROM Payments WHERE Id='Jq74mCczmFXk1tC10GB')", SQL_NTS);
SQLINTEGER rowCount = 0;
SQLRowCount(hstmt, &rowCount);