// Build metadata for each result column
func buildResultColumnDefinitions(stmtHandle odbc.SQLHandle, sqlStmt string) ([]resultColumnDef, odbc.SQLReturn) {
//Get number of result columns
var numColumns odbc.SQLSMALLINT
ret := odbc.SQLNumResultCols(stmtHandle, &numColumns)
if isError(ret) {
errorStatement(stmtHandle, sqlStmt)
}
resultColumnDefs := make([]resultColumnDef, 0, numColumns)
for colNum, lNumColumns := odbc.SQLSMALLINT(1), numColumns; colNum <= lNumColumns; colNum++ {
//Get odbc.SQL type
var sqlType odbc.SQLLEN
ret := odbc.SQLColAttribute(stmtHandle, odbc.SQLUSMALLINT(colNum), odbc.SQL_COLUMN_TYPE, 0, 0, nil, &sqlType)
if isError(ret) {
errorStatement(stmtHandle, sqlStmt)
}
/* Disabled because it is no longer needed
//Get length
var length odbc.SQLLEN
ret = odbc.SQLColAttribute(stmtHandle, odbc.SQLUSMALLINT(colNum), odbc.SQL_COLUMN_LENGTH, 0, 0, nil, &length)
if isError(ret) {
errorStatement(stmtHandle, sqlStmt)
}
//If the type is a CHAR or VARCHAR, add 4 to the length
if odbc.SQLDataType(sqlType) == odbc.SQL_CHAR || odbc.SQLDataType(sqlType) == odbc.SQL_VARCHAR || odbc.SQLDataType(sqlType) == odbc.SQL_WCHAR || odbc.SQLDataType(sqlType) == odbc.SQL_WVARCHAR {
length = length + 4
} */
//Get name
const namelength = 1000
nameArr := make([]uint16, namelength)
ret = odbc.SQLColAttribute(stmtHandle, odbc.SQLUSMALLINT(colNum), odbc.SQL_DESC_LABEL, uintptr(unsafe.Pointer(&nameArr[0])), namelength, nil, nil)
if isError(ret) {
errorStatement(stmtHandle, sqlStmt)
}
name := syscall.UTF16ToString(nameArr)
//For numeric and decimal types, get the precision
var precision odbc.SQLLEN
if odbc.SQLDataType(sqlType) == odbc.SQL_NUMERIC || odbc.SQLDataType(sqlType) == odbc.SQL_DECIMAL {
ret = odbc.SQLColAttribute(stmtHandle, odbc.SQLUSMALLINT(colNum), odbc.SQL_COLUMN_PRECISION, 0, 0, nil, &precision)
if isError(ret) {
errorStatement(stmtHandle, sqlStmt)
}
}
//For numeric and decimal types, get the scale
var scale odbc.SQLLEN
if odbc.SQLDataType(sqlType) == odbc.SQL_NUMERIC || odbc.SQLDataType(sqlType) == odbc.SQL_DECIMAL {
ret = odbc.SQLColAttribute(stmtHandle, odbc.SQLUSMALLINT(colNum), odbc.SQL_COLUMN_SCALE, 0, 0, nil, &scale)
if isError(ret) {
errorStatement(stmtHandle, sqlStmt)
}
}
col := resultColumnDef{RecNum: colNum, DataType: odbc.SQLDataType(sqlType), Name: name, Precision: precision, Scale: scale}
resultColumnDefs = append(resultColumnDefs, col)
}
return resultColumnDefs, odbc.SQL_SUCCESS
}
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
}