// Prepare returns a prepared statement, bound to this connection
func (c *connection) Prepare(query string) (driver.Stmt, error) {
// Allocate the statement handle
var stmtHandle odbc.SQLHandle
ret := odbc.SQLAllocHandle(odbc.SQL_HANDLE_STMT, c.handle, &stmtHandle)
if isError(ret) {
return nil, errorConnection(c.handle)
}
// Set the query timeout
ret = odbc.SQLSetStmtAttr(stmtHandle, odbc.SQL_ATTR_QUERY_TIMEOUT, odbc.SQLPOINTER(queryTimeout.Seconds()), odbc.SQL_IS_INTEGER)
if isError(ret) {
return nil, errorStatement(stmtHandle, query)
}
// Get the statement descriptor table
var stmtDescHandle odbc.SQLHandle
ret = odbc.SQLGetStmtAttr(stmtHandle, odbc.SQL_ATTR_APP_PARAM_DESC, uintptr(unsafe.Pointer(&stmtDescHandle)), 0, nil)
if isError(ret) {
return nil, errorConnection(c.handle)
}
// Parse query options
queryOptions, err := parseQueryOptions(query)
if err != nil {
return nil, err
}
// Remove query options from SQL query
query = removeOptions(query)
// Create new statement
stmt := &statement{handle: stmtHandle, stmtDescHandle: stmtDescHandle, sqlStmt: query, conn: c, queryOptions: queryOptions}
// Add to map of statements owned by the connection
c.statements[stmt] = true
//Add a finalizer
runtime.SetFinalizer(stmt, (*statement).Close)
return stmt, nil
}
func (stmt *statement) Query(args []driver.Value) (driver.Rows, error) {
//Clear any existing bind values
stmt.bindValues = make([]interface{}, len(args)+1)
//Bind the parameters
bindParameters, err := stmt.convertToBindParameters(args)
if err != nil {
return nil, err
}
stmt.bindParameters(bindParameters)
//If rows is not nil, close rows and set to nil
if stmt.rows != nil {
stmt.rows.Close()
stmt.rows = nil
}
//Execute SQL statement
sqlStmtSqlPtr := (*odbc.SQLCHAR)(unsafe.Pointer(syscall.StringToUTF16Ptr(stmt.sqlStmt)))
ret := odbc.SQLExecDirect(stmt.handle, sqlStmtSqlPtr, odbc.SQL_NTS)
if isError(ret) {
return nil, errorStatement(stmt.handle, fmt.Sprintf("SQL Stmt: %v\nBind Values: %v", stmt.sqlStmt, stmt.formatBindValues()))
}
//Get row descriptor handle
var descRowHandle odbc.SQLHandle
ret = odbc.SQLGetStmtAttr(stmt.handle, odbc.SQL_ATTR_APP_ROW_DESC, uintptr(unsafe.Pointer(&descRowHandle)), 0, nil)
if isError(ret) {
return nil, errorStatement(stmt.handle, fmt.Sprintf("SQL Stmt: %v\nBind Values: %v", stmt.sqlStmt, stmt.formatBindValues()))
}
//Check to see if the query option ResultSetNum was passed and if so, iterate through result sets
optionValue, optionFound := getOptionValue(stmt.queryOptions, ResultSetNum)
if optionFound {
for counter, resultSetNum := 0, int(optionValue.(float64)); counter < resultSetNum; counter++ {
ret := odbc.SQLMoreResults(stmt.handle)
if isError(ret) {
return nil, errorStatement(stmt.handle, fmt.Sprintf("SQL Stmt: %v", stmt.sqlStmt))
}
}
} else {
//If query option ResultSetNum was not passed, iterate through result sets until at least one column is found
for {
var numColumns odbc.SQLSMALLINT
ret := odbc.SQLNumResultCols(stmt.handle, &numColumns)
if isError(ret) {
return nil, errorStatement(stmt.handle, fmt.Sprintf("SQL Stmt: %v", stmt.sqlStmt))
}
if numColumns > 0 {
break
} else {
ret := odbc.SQLMoreResults(stmt.handle)
if isError(ret) {
return nil, errorStatement(stmt.handle, fmt.Sprintf("SQL Stmt: %v", stmt.sqlStmt))
}
}
}
}
//Get definition of result columns
resultColumnDefs, ret := buildResultColumnDefinitions(stmt.handle, stmt.sqlStmt)
if isError(ret) {
return nil, errorStatement(stmt.handle, fmt.Sprintf("SQL Stmt: %v\nBind Values: %v", stmt.sqlStmt, stmt.formatBindValues()))
}
//Make a slice of the column names
columnNames := make([]string, len(resultColumnDefs))
for index, resultCol := range resultColumnDefs {
columnNames[index] = fmt.Sprint(resultCol.Name)
}
//Create rows
stmt.rows = &rows{handle: stmt.handle, descHandle: descRowHandle, isBeforeFirst: true, resultColumnDefs: resultColumnDefs, resultColumnNames: columnNames, sqlStmt: stmt.sqlStmt}
//Add a finalizer
runtime.SetFinalizer(stmt.rows, (*rows).Close)
return stmt.rows, nil
}