gorm/dialect_mssql.go

114 lines
2.9 KiB
Go

package gorm
import (
"fmt"
"reflect"
"strings"
"time"
)
type mssql struct {
commonDialect
}
func init() {
RegisterDialect("mssql", &mssql{})
}
func (mssql) DataTypeOf(field *StructField) string {
var dataValue, sqlType, size, additionalType = ParseFieldStructForDialect(field)
if sqlType == "" {
switch dataValue.Kind() {
case reflect.Bool:
sqlType = "bit"
case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uintptr:
if _, ok := field.TagSettings["AUTO_INCREMENT"]; ok || field.IsPrimaryKey {
sqlType = "int IDENTITY(1,1)"
} else {
sqlType = "int"
}
case reflect.Int64, reflect.Uint64:
if _, ok := field.TagSettings["AUTO_INCREMENT"]; ok || field.IsPrimaryKey {
sqlType = "bigint IDENTITY(1,1)"
} else {
sqlType = "bigint"
}
case reflect.Float32, reflect.Float64:
sqlType = "float"
case reflect.String:
if size > 0 && size < 65532 {
sqlType = fmt.Sprintf("nvarchar(%d)", size)
} else {
sqlType = "text"
}
case reflect.Struct:
if _, ok := dataValue.Interface().(time.Time); ok {
sqlType = "datetime2"
}
default:
if _, ok := dataValue.Interface().([]byte); ok {
if size > 0 && size < 65532 {
sqlType = fmt.Sprintf("varchar(%d)", size)
} else {
sqlType = "text"
}
}
}
}
if sqlType == "" {
panic(fmt.Sprintf("invalid sql type %s (%s) for mssql", dataValue.Type().Name(), dataValue.Kind().String()))
}
if strings.TrimSpace(additionalType) == "" {
return sqlType
}
return fmt.Sprintf("%v %v", sqlType, additionalType)
}
func (s mssql) HasIndex(tableName string, indexName string) bool {
var count int
s.db.QueryRow("SELECT count(*) FROM sys.indexes WHERE name=? AND object_id=OBJECT_ID(?)", indexName, tableName).Scan(&count)
return count > 0
}
func (s mssql) RemoveIndex(tableName string, indexName string) error {
_, err := s.db.Exec(fmt.Sprintf("DROP INDEX %v ON %v", indexName, s.Quote(tableName)))
return err
}
func (s mssql) HasTable(tableName string) bool {
var count int
s.db.QueryRow("SELECT count(*) FROM INFORMATION_SCHEMA.tables WHERE table_name = ? AND table_catalog = ?", tableName, s.currentDatabase()).Scan(&count)
return count > 0
}
func (s mssql) HasColumn(tableName string, columnName string) bool {
var count int
s.db.QueryRow("SELECT count(*) FROM information_schema.columns WHERE table_catalog = ? AND table_name = ? AND column_name = ?", s.currentDatabase(), tableName, columnName).Scan(&count)
return count > 0
}
func (s mssql) currentDatabase() (name string) {
s.db.QueryRow("SELECT DB_NAME() AS [Current Database]").Scan(&name)
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
}