Refactor dialect

leeopus · Jan 18, 2016 · e159ca1 · e159ca1
1 parent 896ee53
commit e159ca1
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Showing 11 changed files with 123 additions and 137 deletions.
diff --git a/dialect.go b/dialect.go
@@ -7,17 +7,19 @@ import (
 
 type Dialect interface {
 	BinVar(i int) string
-	SupportLastInsertId() bool
-	HasTop() bool
-	SqlTag(value reflect.Value, size int, autoIncrease bool) string
-	ReturningStr(tableName, key string) string
-	SelectFromDummyTable() string
 	Quote(key string) string
-	HasTable(scope *Scope, tableName string) bool
-	HasColumn(scope *Scope, tableName string, columnName string) bool
+	SqlTag(value reflect.Value, size int, autoIncrease bool) string
+
 	HasIndex(scope *Scope, tableName string, indexName string) bool
 	RemoveIndex(scope *Scope, indexName string)
+	HasTable(scope *Scope, tableName string) bool
+	HasColumn(scope *Scope, tableName string, columnName string) bool
 	CurrentDatabase(scope *Scope) string
+
+	ReturningStr(tableName, key string) string
+	LimitAndOffsetSQL(limit, offset int) string
+	SelectFromDummyTable() string
+	SupportLastInsertId() bool
 }
 
 func NewDialect(driver string) Dialect {

diff --git a/dialect_common.go b/dialect_common.go
@@ -12,12 +12,8 @@ func (commonDialect) BinVar(i int) string {
 	return "$$" // ?
 }
 
-func (commonDialect) SupportLastInsertId() bool {
-	return true
-}
-
-func (commonDialect) HasTop() bool {
-	return false
+func (commonDialect) Quote(key string) string {
+	return fmt.Sprintf(`"%s"`, key)
 }
 
 func (commonDialect) SqlTag(value reflect.Value, size int, autoIncrease bool) string {
@@ -56,16 +52,17 @@ func (commonDialect) SqlTag(value reflect.Value, size int, autoIncrease bool) st
 	panic(fmt.Sprintf("invalid sql type %s (%s) for commonDialect", value.Type().Name(), value.Kind().String()))
 }
 
-func (commonDialect) ReturningStr(tableName, key string) string {
-	return ""
-}
-
-func (commonDialect) SelectFromDummyTable() string {
-	return ""
+func (c commonDialect) HasIndex(scope *Scope, tableName string, indexName string) bool {
+	var (
+		count        int
+		databaseName = c.CurrentDatabase(scope)
+	)
+	c.RawScanInt(scope, &count, "SELECT count(*) FROM INFORMATION_SCHEMA.STATISTICS WHERE table_schema = ? AND table_name = ? AND index_name = ?", databaseName, tableName, indexName)
+	return count > 0
 }
 
-func (commonDialect) Quote(key string) string {
-	return fmt.Sprintf(`"%s"`, key)
+func (commonDialect) RemoveIndex(scope *Scope, indexName string) {
+	scope.Err(scope.NewDB().Exec(fmt.Sprintf("DROP INDEX %v ON %v", indexName, scope.QuotedTableName())).Error)
 }
 
 func (c commonDialect) HasTable(scope *Scope, tableName string) bool {
@@ -86,19 +83,6 @@ func (c commonDialect) HasColumn(scope *Scope, tableName string, columnName stri
 	return count > 0
 }
 
-func (c commonDialect) HasIndex(scope *Scope, tableName string, indexName string) bool {
-	var (
-		count        int
-		databaseName = c.CurrentDatabase(scope)
-	)
-	c.RawScanInt(scope, &count, "SELECT count(*) FROM INFORMATION_SCHEMA.STATISTICS WHERE table_schema = ? AND table_name = ? AND index_name = ?", databaseName, tableName, indexName)
-	return count > 0
-}
-
-func (commonDialect) RemoveIndex(scope *Scope, indexName string) {
-	scope.Err(scope.NewDB().Exec(fmt.Sprintf("DROP INDEX %v ON %v", indexName, scope.QuotedTableName())).Error)
-}
-
 // RawScanInt scans the first column of the first row into the `scan' int pointer.
 // This function captures raw query errors and propagates them to the original scope.
 func (commonDialect) RawScanInt(scope *Scope, scanPtr *int, query string, args ...interface{}) {
@@ -115,3 +99,25 @@ func (commonDialect) CurrentDatabase(scope *Scope) (name string) {
 	scope.Err(scope.NewDB().Raw("SELECT DATABASE()").Row().Scan(&name))
 	return
 }
+
+func (commonDialect) ReturningStr(tableName, key string) string {
+	return ""
+}
+
+func (commonDialect) LimitAndOffsetSQL(limit, offset int) (sql string) {
+	if limit >= 0 {
+		sql += fmt.Sprintf(" LIMIT %d", limit)
+	}
+	if offset >= 0 {
+		sql += fmt.Sprintf(" OFFSET %d", offset)
+	}
+	return
+}
+
+func (commonDialect) SelectFromDummyTable() string {
+	return ""
+}
+
+func (commonDialect) SupportLastInsertId() bool {
+	return true
+}
diff --git a/dialect_mssql.go b/dialect_mssql.go
@@ -10,10 +10,6 @@ type mssql struct {
 	commonDialect
 }
 
-func (mssql) HasTop() bool {
-	return true
-}
-
 func (mssql) SqlTag(value reflect.Value, size int, autoIncrease bool) string {
 	switch value.Kind() {
 	case reflect.Bool:
@@ -50,6 +46,12 @@ func (mssql) SqlTag(value reflect.Value, size int, autoIncrease bool) string {
 	panic(fmt.Sprintf("invalid sql type %s (%s) for mssql", value.Type().Name(), value.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
@@ -68,13 +70,24 @@ func (s mssql) HasColumn(scope *Scope, tableName string, columnName string) bool
 	return count > 0
 }
 
-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) 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
+}
diff --git a/dialect_mysql.go b/dialect_mysql.go
@@ -10,6 +10,10 @@ type mysql struct {
 	commonDialect
 }
 
+func (mysql) Quote(key string) string {
+	return fmt.Sprintf("`%s`", key)
+}
+
 func (mysql) SqlTag(value reflect.Value, size int, autoIncrease bool) string {
 	switch value.Kind() {
 	case reflect.Bool:
@@ -56,15 +60,11 @@ func (mysql) SqlTag(value reflect.Value, size int, autoIncrease bool) string {
 	panic(fmt.Sprintf("invalid sql type %s (%s) for mysql", value.Type().Name(), value.Kind().String()))
 }
 
-func (mysql) Quote(key string) string {
-	return fmt.Sprintf("`%s`", key)
+func (s mysql) CurrentDatabase(scope *Scope) (name string) {
+	s.RawScanString(scope, &name, "SELECT DATABASE()")
+	return
 }
 
 func (mysql) SelectFromDummyTable() string {
 	return "FROM DUAL"
 }
-
-func (s mysql) CurrentDatabase(scope *Scope) (name string) {
-	s.RawScanString(scope, &name, "SELECT DATABASE()")
-	return
-}
diff --git a/dialect_postgres.go b/dialect_postgres.go
@@ -19,10 +19,6 @@ func (postgres) BinVar(i int) string {
 	return fmt.Sprintf("$%v", i)
 }
 
-func (postgres) SupportLastInsertId() bool {
-	return false
-}
-
 func (postgres) SqlTag(value reflect.Value, size int, autoIncrease bool) string {
 	switch value.Kind() {
 	case reflect.Bool:
@@ -62,23 +58,14 @@ func (postgres) SqlTag(value reflect.Value, size int, autoIncrease bool) string
 	panic(fmt.Sprintf("invalid sql type %s (%s) for postgres", value.Type().Name(), value.Kind().String()))
 }
 
-var byteType = reflect.TypeOf(uint8(0))
-
-func isByteArrayOrSlice(value reflect.Value) bool {
-	return (value.Kind() == reflect.Array || value.Kind() == reflect.Slice) && value.Type().Elem() == byteType
-}
-
-func isUUID(value reflect.Value) bool {
-	if value.Kind() != reflect.Array || value.Type().Len() != 16 {
-		return false
-	}
-	typename := value.Type().Name()
-	lower := strings.ToLower(typename)
-	return "uuid" == lower || "guid" == lower
+func (s postgres) HasIndex(scope *Scope, tableName string, indexName string) bool {
+	var count int
+	s.RawScanInt(scope, &count, "SELECT count(*) FROM pg_indexes WHERE tablename = ? AND indexname = ?", tableName, indexName)
+	return count > 0
 }
 
-func (s postgres) ReturningStr(tableName, key string) string {
-	return fmt.Sprintf("RETURNING %v.%v", tableName, key)
+func (postgres) RemoveIndex(scope *Scope, indexName string) {
+	scope.Err(scope.NewDB().Exec(fmt.Sprintf("DROP INDEX %v", indexName)).Error)
 }
 
 func (s postgres) HasTable(scope *Scope, tableName string) bool {
@@ -93,19 +80,17 @@ func (s postgres) HasColumn(scope *Scope, tableName string, columnName string) b
 	return count > 0
 }
 
-func (postgres) RemoveIndex(scope *Scope, indexName string) {
-	scope.Err(scope.NewDB().Exec(fmt.Sprintf("DROP INDEX %v", indexName)).Error)
+func (s postgres) CurrentDatabase(scope *Scope) (name string) {
+	s.RawScanString(scope, &name, "SELECT CURRENT_DATABASE()")
+	return
 }
 
-func (s postgres) HasIndex(scope *Scope, tableName string, indexName string) bool {
-	var count int
-	s.RawScanInt(scope, &count, "SELECT count(*) FROM pg_indexes WHERE tablename = ? AND indexname = ?", tableName, indexName)
-	return count > 0
+func (s postgres) ReturningStr(tableName, key string) string {
+	return fmt.Sprintf("RETURNING %v.%v", tableName, key)
 }
 
-func (s postgres) CurrentDatabase(scope *Scope) (name string) {
-	s.RawScanString(scope, &name, "SELECT CURRENT_DATABASE()")
-	return
+func (postgres) SupportLastInsertId() bool {
+	return false
 }
 
 var hstoreType = reflect.TypeOf(Hstore{})
@@ -152,3 +137,16 @@ func (h *Hstore) Scan(value interface{}) error {
 
 	return nil
 }
+
+func isByteArrayOrSlice(value reflect.Value) bool {
+	return (value.Kind() == reflect.Array || value.Kind() == reflect.Slice) && value.Type().Elem() == reflect.TypeOf(uint8(0))
+}
+
+func isUUID(value reflect.Value) bool {
+	if value.Kind() != reflect.Array || value.Type().Len() != 16 {
+		return false
+	}
+	typename := value.Type().Name()
+	lower := strings.ToLower(typename)
+	return "uuid" == lower || "guid" == lower
+}
diff --git a/dialect_sqlite3.go b/dialect_sqlite3.go
@@ -43,26 +43,26 @@ func (sqlite3) SqlTag(value reflect.Value, size int, autoIncrease bool) string {
 	panic(fmt.Sprintf("invalid sql type %s (%s) for sqlite3", value.Type().Name(), value.Kind().String()))
 }
 
-func (s sqlite3) HasTable(scope *Scope, tableName string) bool {
+func (s sqlite3) HasIndex(scope *Scope, tableName string, indexName string) bool {
 	var count int
-	s.RawScanInt(scope, &count, "SELECT count(*) FROM sqlite_master WHERE type='table' AND name=?", tableName)
+	s.RawScanInt(scope, &count, fmt.Sprintf("SELECT count(*) FROM sqlite_master WHERE tbl_name = ? AND sql LIKE '%%INDEX %v ON%%'", indexName), tableName)
 	return count > 0
 }
 
-func (s sqlite3) HasColumn(scope *Scope, tableName string, columnName string) bool {
-	var count int
-	s.RawScanInt(scope, &count, fmt.Sprintf("SELECT count(*) FROM sqlite_master WHERE tbl_name = ? AND (sql LIKE '%%(\"%v\" %%' OR sql LIKE '%%,\"%v\" %%' OR sql LIKE '%%, \"%v\" %%' OR sql LIKE '%%( %v %%' OR sql LIKE '%%, %v %%' OR sql LIKE '%%,%v %%');\n", columnName, columnName, columnName, columnName, columnName, columnName), tableName)
-	return count > 0
+func (sqlite3) RemoveIndex(scope *Scope, indexName string) {
+	scope.Err(scope.NewDB().Exec(fmt.Sprintf("DROP INDEX %v", indexName)).Error)
 }
 
-func (s sqlite3) HasIndex(scope *Scope, tableName string, indexName string) bool {
+func (s sqlite3) HasTable(scope *Scope, tableName string) bool {
 	var count int
-	s.RawScanInt(scope, &count, fmt.Sprintf("SELECT count(*) FROM sqlite_master WHERE tbl_name = ? AND sql LIKE '%%INDEX %v ON%%'", indexName), tableName)
+	s.RawScanInt(scope, &count, "SELECT count(*) FROM sqlite_master WHERE type='table' AND name=?", tableName)
 	return count > 0
 }
 
-func (sqlite3) RemoveIndex(scope *Scope, indexName string) {
-	scope.Err(scope.NewDB().Exec(fmt.Sprintf("DROP INDEX %v", indexName)).Error)
+func (s sqlite3) HasColumn(scope *Scope, tableName string, columnName string) bool {
+	var count int
+	s.RawScanInt(scope, &count, fmt.Sprintf("SELECT count(*) FROM sqlite_master WHERE tbl_name = ? AND (sql LIKE '%%(\"%v\" %%' OR sql LIKE '%%,\"%v\" %%' OR sql LIKE '%%, \"%v\" %%' OR sql LIKE '%%( %v %%' OR sql LIKE '%%, %v %%' OR sql LIKE '%%,%v %%');\n", columnName, columnName, columnName, columnName, columnName, columnName), tableName)
+	return count > 0
 }
 
 func (sqlite3) CurrentDatabase(scope *Scope) (name string) {

diff --git a/main.go b/main.go
@@ -146,12 +146,12 @@ func (s *DB) Not(query interface{}, args ...interface{}) *DB {
 	return s.clone().search.Not(query, args...).db
 }
 
-func (s *DB) Limit(value interface{}) *DB {
-	return s.clone().search.Limit(value).db
+func (s *DB) Limit(limit int) *DB {
+	return s.clone().search.Limit(limit).db
 }
 
-func (s *DB) Offset(value interface{}) *DB {
-	return s.clone().search.Offset(value).db
+func (s *DB) Offset(offset int) *DB {
+	return s.clone().search.Offset(offset).db
 }
 
 func (s *DB) Order(value string, reorder ...bool) *DB {

diff --git a/main_private.go b/main_private.go
@@ -10,7 +10,7 @@ func (s *DB) clone() *DB {
 	}
 
 	if s.search == nil {
-		db.search = &search{}
+		db.search = &search{limit: -1, offset: -1}
 	} else {
 		db.search = s.search.clone()
 	}

diff --git a/scope.go b/scope.go
@@ -272,7 +272,7 @@ func (scope *Scope) QuotedTableName() (name string) {
 // CombinedConditionSql get combined condition sql
 func (scope *Scope) CombinedConditionSql() string {
 	return scope.joinsSql() + scope.whereSql() + scope.groupSql() +
-		scope.havingSql() + scope.orderSql() + scope.limitSql() + scope.offsetSql()
+		scope.havingSql() + scope.orderSql() + scope.limitAndOffsetSql()
 }
 
 // FieldByName find gorm.Field with name and db name