// DropAndCreateTable удаляет таблицу, если она уже существует и создает заново
func DropAndCreateTable(schema string, tableName string, db *sqlx.DB) (bool, error) {
var err error
var rows *sqlx.Rows
// Проверяем нет ли такой таблицы в базе
rows, err = db.Queryx("SELECT to_regclass('" + tableName + "');")
if err != nil {
//fmt.Println("Error on check table '"+tableName+"':", err)
return false, err
}
defer rows.Close()
// И если есть удаляем
rowsCount := 0
for rows.Next() {
rowsCount++
}
if rowsCount > 0 {
_, err = db.Exec("DROP TABLE IF EXISTS " + tableName + ";")
if err != nil {
//fmt.Println("Error on drop table '"+tableName+"':", err)
return false, err
}
}
// Создаем таблицу
_, err = db.Exec(schema)
if err != nil {
//fmt.Println("Error on create table '"+tableName+"':", err)
return false, err
}
return true, nil
}
// ScanOne returns the instance, if any, returned from sql query
func ScanOne(instance interface{}, rows *sqlx.Rows) error {
defer rows.Close()
for rows.Next() {
if err := rows.StructScan(instance); err != nil {
return err
}
}
return nil
}
// QueryScan executes the query in builder and loads the resulting data into
// one or more destinations.
//
// Returns ErrNotFound if no value was found, and it was therefore not set.
func queryScalar(execer *Execer, destinations ...interface{}) error {
fullSQL, args, blob, err := cacheOrSQL(execer)
if err != nil {
return err
}
if blob != nil {
err = json.Unmarshal(blob, &destinations)
if err == nil {
return nil
}
// log it and fallthrough to let the query continue
logger.Warn("queryScalar.2: Could not unmarshal cache data. Continuing with query")
}
defer logExecutionTime(time.Now(), fullSQL, args)
// Run the query:
var rows *sqlx.Rows
if args == nil {
rows, err = execer.database.Queryx(fullSQL)
} else {
rows, err = execer.database.Queryx(fullSQL, args...)
}
if err != nil {
return logSQLError(err, "QueryScalar.load_value.query", fullSQL, args)
}
defer rows.Close()
if rows.Next() {
err = rows.Scan(destinations...)
if err != nil {
return logSQLError(err, "QueryScalar.load_value.scan", fullSQL, args)
}
setCache(execer, destinations, dtStruct)
return nil
}
if err := rows.Err(); err != nil {
return logSQLError(err, "QueryScalar.load_value.rows_err", fullSQL, args)
}
return dat.ErrNotFound
}
// queryJSONBlob executes the query in builder and loads the resulting data
// into a blob. If a single item is to be returned, set single to true.
//
// Returns ErrNotFound if nothing was found
func queryJSONBlob(execer *Execer, single bool) ([]byte, error) {
fullSQL, args, blob, err := cacheOrSQL(execer)
if err != nil {
return nil, err
}
if blob != nil {
return blob, nil
}
defer logExecutionTime(time.Now(), fullSQL, args)
var rows *sqlx.Rows
// Run the query:
if args == nil {
rows, err = execer.database.Queryx(fullSQL)
} else {
rows, err = execer.database.Queryx(fullSQL, args...)
}
if err != nil {
return nil, logSQLError(err, "queryJSONStructs", fullSQL, args)
}
// TODO optimize this later, may be better to
var buf bytes.Buffer
i := 0
if single {
defer rows.Close()
for rows.Next() {
if i == 1 {
if dat.Strict {
logSQLError(errors.New("Multiple results returned"), "Expected single result", fullSQL, args)
logger.Fatal("Expected single result, got many")
} else {
break
}
}
i++
err = rows.Scan(&blob)
if err != nil {
return nil, err
}
buf.Write(blob)
}
} else {
defer rows.Close()
for rows.Next() {
if i == 0 {
buf.WriteRune('[')
} else {
buf.WriteRune(',')
}
i++
err = rows.Scan(&blob)
if err != nil {
return nil, err
}
buf.Write(blob)
}
if i > 0 {
buf.WriteRune(']')
}
}
if i == 0 {
return nil, sql.ErrNoRows
}
blob = buf.Bytes()
setCache(execer, blob, dtBytes)
return blob, nil
}
// QuerySlice executes the query in builder and loads the resulting data into a
// slice of primitive values
//
// Returns ErrNotFound if no value was found, and it was therefore not set.
func querySlice(execer *Execer, dest interface{}) error {
// Validate the dest and reflection values we need
// This must be a pointer to a slice
valueOfDest := reflect.ValueOf(dest)
kindOfDest := valueOfDest.Kind()
if kindOfDest != reflect.Ptr {
panic("invalid type passed to LoadValues. Need a pointer to a slice")
}
// This must a slice
valueOfDest = reflect.Indirect(valueOfDest)
kindOfDest = valueOfDest.Kind()
if kindOfDest != reflect.Slice {
panic("invalid type passed to LoadValues. Need a pointer to a slice")
}
recordType := valueOfDest.Type().Elem()
recordTypeIsPtr := recordType.Kind() == reflect.Ptr
if recordTypeIsPtr {
reflect.ValueOf(dest)
}
fullSQL, args, blob, err := cacheOrSQL(execer)
if err != nil {
return err
}
if blob != nil {
err = json.Unmarshal(blob, &dest)
if err == nil {
return nil
}
// log it and fallthrough to let the query continue
logger.Warn("querySlice.2: Could not unmarshal cache data. Continuing with query")
}
defer logExecutionTime(time.Now(), fullSQL, args)
var rows *sqlx.Rows
if args == nil {
rows, err = execer.database.Queryx(fullSQL)
} else {
rows, err = execer.database.Queryx(fullSQL, args...)
}
if err != nil {
return logSQLError(err, "querySlice.load_all_values.query", fullSQL, args)
}
sliceValue := valueOfDest
defer rows.Close()
for rows.Next() {
// Create a new value to store our row:
pointerToNewValue := reflect.New(recordType)
newValue := reflect.Indirect(pointerToNewValue)
err = rows.Scan(pointerToNewValue.Interface())
if err != nil {
return logSQLError(err, "querySlice.load_all_values.scan", fullSQL, args)
}
// Append our new value to the slice:
sliceValue = reflect.Append(sliceValue, newValue)
}
valueOfDest.Set(sliceValue)
if err := rows.Err(); err != nil {
return logSQLError(err, "querySlice.load_all_values.rows_err", fullSQL, args)
}
setCache(execer, dest, dtStruct)
return nil
}