gorm/dialect_mssql.go

100 lines
2.5 KiB
Go

package gorm
import (
"fmt"
"reflect"
"strconv"
"time"
)
type mssql struct {
commonDialect
}
func (mssql) DataTypeOf(dataValue reflect.Value, tagSettings map[string]string) string {
var size int
if num, ok := tagSettings["SIZE"]; ok {
size, _ = strconv.Atoi(num)
}
switch dataValue.Kind() {
case reflect.Bool:
return "bit"
case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uintptr:
if _, ok := tagSettings["AUTO_INCREMENT"]; ok {
return "int IDENTITY(1,1)"
}
return "int"
case reflect.Int64, reflect.Uint64:
if _, ok := tagSettings["AUTO_INCREMENT"]; ok {
return "bigint IDENTITY(1,1)"
}
return "bigint"
case reflect.Float32, reflect.Float64:
return "float"
case reflect.String:
if size > 0 && size < 65532 {
return fmt.Sprintf("nvarchar(%d)", size)
}
return "text"
case reflect.Struct:
if _, ok := dataValue.Interface().(time.Time); ok {
return "datetime2"
}
default:
if _, ok := dataValue.Interface().([]byte); ok {
if size > 0 && size < 65532 {
return fmt.Sprintf("varchar(%d)", size)
}
return "text"
}
}
panic(fmt.Sprintf("invalid sql type %s (%s) for mssql", dataValue.Type().Name(), dataValue.Kind().String()))
}
func (s mssql) HasIndex(scope *Scope, tableName string, indexName string) bool {
var count int
s.RawScanInt(scope, &count, "SELECT count(*) FROM sys.indexes WHERE name=? AND object_id=OBJECT_ID(?)", indexName, tableName)
return count > 0
}
func (s mssql) HasTable(scope *Scope, tableName string) bool {
var (
count int
databaseName = s.currentDatabase(scope)
)
s.RawScanInt(scope, &count, "SELECT count(*) FROM INFORMATION_SCHEMA.tables WHERE table_name = ? AND table_catalog = ?", tableName, databaseName)
return count > 0
}
func (s mssql) HasColumn(scope *Scope, tableName string, columnName string) bool {
var (
count int
databaseName = s.currentDatabase(scope)
)
s.RawScanInt(scope, &count, "SELECT count(*) FROM information_schema.columns WHERE table_catalog = ? AND table_name = ? AND column_name = ?", databaseName, tableName, columnName)
return count > 0
}
func (s mssql) currentDatabase(scope *Scope) (name string) {
s.RawScanString(scope, &name, "SELECT DB_NAME() AS [Current Database]")
return
}
func (mssql) LimitAndOffsetSQL(limit, offset int) (sql string) {
if limit < 0 && offset < 0 {
return
}
if offset < 0 {
offset = 0
}
sql += fmt.Sprintf(" OFFSET %d ROWS", offset)
if limit >= 0 {
sql += fmt.Sprintf(" FETCH NEXT %d ROWS ONLY", limit)
}
return
}