Some refactor (#2292)

replace #2285

Reviewed-on: https://gitea.com/xorm/xorm/pulls/2292

dialects/dialect.go

@@ -85,8 +85,6 @@ type Dialect interface {
 	AddColumnSQL(tableName string, col *schemas.Column) string
 	ModifyColumnSQL(tableName string, col *schemas.Column) string
 
-	ForUpdateSQL(query string) string
-
 	Filters() []Filter
 	SetParams(params map[string]string)
 }
@@ -245,11 +243,6 @@ func (db *Base) ModifyColumnSQL(tableName string, col *schemas.Column) string {
 	return fmt.Sprintf("ALTER TABLE %s MODIFY COLUMN %s", db.quoter.Quote(tableName), s)
 }
 
-// ForUpdateSQL returns for updateSQL
-func (db *Base) ForUpdateSQL(query string) string {
-	return query + " FOR UPDATE"
-}
-
 // SetParams set params
 func (db *Base) SetParams(params map[string]string) {
 }

dialects/mssql.go

@@ -669,10 +669,6 @@ func (db *mssql) CreateTableSQL(ctx context.Context, queryer core.Queryer, table
 	return b.String(), true, nil
 }
 
-func (db *mssql) ForUpdateSQL(query string) string {
-	return query
-}
-
 func (db *mssql) Filters() []Filter {
 	return []Filter{}
 }

dialects/sqlite3.go

@@ -193,11 +193,11 @@ func (db *sqlite3) Features() *DialectFeatures {
 func (db *sqlite3) SetQuotePolicy(quotePolicy QuotePolicy) {
 	switch quotePolicy {
 	case QuotePolicyNone:
-		var q = sqlite3Quoter
+		q := sqlite3Quoter
 		q.IsReserved = schemas.AlwaysNoReserve
 		db.quoter = q
 	case QuotePolicyReserved:
-		var q = sqlite3Quoter
+		q := sqlite3Quoter
 		q.IsReserved = db.IsReserved
 		db.quoter = q
 	case QuotePolicyAlways:
@@ -291,10 +291,6 @@ func (db *sqlite3) DropIndexSQL(tableName string, index *schemas.Index) string {
 	return fmt.Sprintf("DROP INDEX %v", db.Quoter().Quote(idxName))
 }
 
-func (db *sqlite3) ForUpdateSQL(query string) string {
-	return query
-}
-
 func (db *sqlite3) IsColumnExist(queryer core.Queryer, ctx context.Context, tableName, colName string) (bool, error) {
 	query := "SELECT * FROM " + tableName + " LIMIT 0"
 	rows, err := queryer.QueryContext(ctx, query)
@@ -320,7 +316,7 @@ func (db *sqlite3) IsColumnExist(queryer core.Queryer, ctx context.Context, tabl
 // splitColStr splits a sqlite col strings as fields
 func splitColStr(colStr string) []string {
 	colStr = strings.TrimSpace(colStr)
-	var results = make([]string, 0, 10)
+	results := make([]string, 0, 10)
 	var lastIdx int
 	var hasC, hasQuote bool
 	for i, c := range colStr {

integrations/session_count_test.go

@@ -89,7 +89,7 @@ func TestCountWithOthers(t *testing.T) {
 	})
 	assert.NoError(t, err)
 
-	total, err := testEngine.OrderBy("`id` desc").Limit(1).Count(new(CountWithOthers))
+	total, err := testEngine.OrderBy("count(`id`) desc").Limit(1).Count(new(CountWithOthers))
 	assert.NoError(t, err)
 	assert.EqualValues(t, 2, total)
 }
@@ -118,11 +118,11 @@ func TestWithTableName(t *testing.T) {
 	})
 	assert.NoError(t, err)
 
-	total, err := testEngine.OrderBy("`id` desc").Count(new(CountWithTableName))
+	total, err := testEngine.OrderBy("count(`id`) desc").Count(new(CountWithTableName))
 	assert.NoError(t, err)
 	assert.EqualValues(t, 2, total)
 
-	total, err = testEngine.OrderBy("`id` desc").Count(CountWithTableName{})
+	total, err = testEngine.OrderBy("count(`id`) desc").Count(CountWithTableName{})
 	assert.NoError(t, err)
 	assert.EqualValues(t, 2, total)
 }

internal/statements/query.go

@@ -7,6 +7,7 @@ package statements
 import (
 	"errors"
 	"fmt"
+	"io"
 	"reflect"
 	"strings"
 
@@ -29,37 +30,15 @@ func (statement *Statement) GenQuerySQL(sqlOrArgs ...interface{}) (string, []int
 		return "", nil, ErrTableNotFound
 	}
 
-	columnStr := statement.ColumnStr()
-	if len(statement.SelectStr) > 0 {
-		columnStr = statement.SelectStr
-	} else {
-		if len(statement.joins) == 0 {
-			if columnStr == "" {
-				if statement.GroupByStr != "" {
-					columnStr = statement.quoteColumnStr(statement.GroupByStr)
-				} else {
-					columnStr = statement.genColumnStr()
-				}
-			}
-		} else {
-			if columnStr == "" {
-				if statement.GroupByStr != "" {
-					columnStr = statement.quoteColumnStr(statement.GroupByStr)
-				} else {
-					columnStr = "*"
-				}
-			}
-		}
-		if columnStr == "" {
-			columnStr = "*"
-		}
-	}
-
 	if err := statement.ProcessIDParam(); err != nil {
 		return "", nil, err
 	}
 
-	return statement.genSelectSQL(columnStr, true, true)
+	buf := builder.NewWriter()
+	if err := statement.writeSelect(buf, statement.genSelectColumnStr(), true); err != nil {
+		return "", nil, err
+	}
+	return buf.String(), buf.Args(), nil
 }
 
 // GenSumSQL generates sum SQL
@@ -81,13 +60,16 @@ func (statement *Statement) GenSumSQL(bean interface{}, columns ...string) (stri
 		}
 		sumStrs = append(sumStrs, fmt.Sprintf("COALESCE(sum(%s),0)", colName))
 	}
-	sumSelect := strings.Join(sumStrs, ", ")
 
 	if err := statement.MergeConds(bean); err != nil {
 		return "", nil, err
 	}
 
-	return statement.genSelectSQL(sumSelect, true, true)
+	buf := builder.NewWriter()
+	if err := statement.writeSelect(buf, strings.Join(sumStrs, ", "), true); err != nil {
+		return "", nil, err
+	}
+	return buf.String(), buf.Args(), nil
 }
 
 // GenGetSQL generates Get SQL
@@ -139,7 +121,11 @@ func (statement *Statement) GenGetSQL(bean interface{}) (string, []interface{},
 		}
 	}
 
-	return statement.genSelectSQL(columnStr, true, true)
+	buf := builder.NewWriter()
+	if err := statement.writeSelect(buf, columnStr, true); err != nil {
+		return "", nil, err
+	}
+	return buf.String(), buf.Args(), nil
 }
 
 // GenCountSQL generates the SQL for counting
@@ -148,8 +134,6 @@ func (statement *Statement) GenCountSQL(beans ...interface{}) (string, []interfa
 		return statement.GenRawSQL(), statement.RawParams, nil
 	}
 
-	var condArgs []interface{}
-	var err error
 	if len(beans) > 0 {
 		if err := statement.SetRefBean(beans[0]); err != nil {
 			return "", nil, err
@@ -176,16 +160,24 @@ func (statement *Statement) GenCountSQL(beans ...interface{}) (string, []interfa
 		subQuerySelect = selectSQL
 	}
 
-	sqlStr, condArgs, err := statement.genSelectSQL(subQuerySelect, false, false)
+	buf := builder.NewWriter()
-	if err != nil {
+	if statement.GroupByStr != "" {
+		if _, err := fmt.Fprintf(buf, "SELECT %s FROM (", selectSQL); err != nil {
+			return "", nil, err
+		}
+	}
+
+	if err := statement.writeSelect(buf, subQuerySelect, false); err != nil {
 		return "", nil, err
 	}
 
 	if statement.GroupByStr != "" {
-		sqlStr = fmt.Sprintf("SELECT %s FROM (%s) sub", selectSQL, sqlStr)
+		if _, err := fmt.Fprintf(buf, ") sub"); err != nil {
+			return "", nil, err
+		}
 	}
 
-	return sqlStr, condArgs, nil
+	return buf.String(), buf.Args(), nil
 }
 
 func (statement *Statement) writeFrom(w *builder.BytesWriter) error {
@@ -218,37 +210,73 @@ func (statement *Statement) writeLimitOffset(w builder.Writer) error {
 	return nil
 }
 
-func (statement *Statement) genSelectSQL(columnStr string, needLimit, needOrderBy bool) (string, []interface{}, error) {
+func (statement *Statement) writeTop(w builder.Writer) error {
-	var (
+	if statement.dialect.URI().DBType != schemas.MSSQL {
-		distinct      string
+		return nil
-		dialect       = statement.dialect
+	}
-		top, whereStr string
+	if statement.LimitN == nil {
-		mssqlCondi    = builder.NewWriter()
+		return nil
-	)
+	}
+	_, err := fmt.Fprintf(w, " TOP %d", *statement.LimitN)
+	return err
+}
 
-	if statement.IsDistinct && !strings.HasPrefix(columnStr, "count") {
+func (statement *Statement) writeDistinct(w builder.Writer) error {
-		distinct = "DISTINCT "
+	if statement.IsDistinct && !strings.HasPrefix(statement.SelectStr, "count(") {
+		_, err := fmt.Fprint(w, " DISTINCT")
+		return err
+	}
+	return nil
+}
+
+func (statement *Statement) writeSelectColumns(w *builder.BytesWriter, columnStr string) error {
+	if _, err := fmt.Fprintf(w, "SELECT "); err != nil {
+		return err
+	}
+	if err := statement.writeDistinct(w); err != nil {
+		return err
+	}
+	if err := statement.writeTop(w); err != nil {
+		return err
+	}
+	_, err := fmt.Fprint(w, " ", columnStr)
+	return err
+}
+
+func (statement *Statement) writeWhere(w *builder.BytesWriter) error {
+	if !statement.cond.IsValid() {
+		return statement.writeMssqlPaginationCond(w)
+	}
+	if _, err := fmt.Fprint(w, " WHERE "); err != nil {
+		return err
+	}
+	if err := statement.cond.WriteTo(statement.QuoteReplacer(w)); err != nil {
+		return err
+	}
+	return statement.writeMssqlPaginationCond(w)
+}
+
+func (statement *Statement) writeForUpdate(w io.Writer) error {
+	if !statement.IsForUpdate {
+		return nil
 	}
 
-	condWriter := builder.NewWriter()
+	if statement.dialect.URI().DBType != schemas.MYSQL {
-	if err := statement.cond.WriteTo(statement.QuoteReplacer(condWriter)); err != nil {
+		return errors.New("only support mysql for update")
-		return "", nil, err
+	}
+	_, err := fmt.Fprint(w, " FOR UPDATE")
+	return err
+}
+
+func (statement *Statement) writeMssqlPaginationCond(w *builder.BytesWriter) error {
+	if statement.dialect.URI().DBType != schemas.MSSQL || statement.Start <= 0 {
+		return nil
 	}
 
-	if condWriter.Len() > 0 {
-		whereStr = " WHERE "
-	}
-
-	pLimitN := statement.LimitN
-	if dialect.URI().DBType == schemas.MSSQL {
-		if pLimitN != nil {
-			LimitNValue := *pLimitN
-			top = fmt.Sprintf("TOP %d ", LimitNValue)
-		}
-		if statement.Start > 0 {
 	if statement.RefTable == nil {
-				return "", nil, errors.New("Unsupported query limit without reference table")
+		return errors.New("unsupported query limit without reference table")
 	}
+
 	var column string
 	if len(statement.RefTable.PKColumns()) == 0 {
 		for _, index := range statement.RefTable.Indexes {
@@ -271,100 +299,94 @@ func (statement *Statement) genSelectSQL(columnStr string, needLimit, needOrderB
 		}
 	}
 
-			if _, err := fmt.Fprintf(mssqlCondi, "(%s NOT IN (SELECT TOP %d %s",
+	subWriter := builder.NewWriter()
+	if _, err := fmt.Fprintf(subWriter, "(%s NOT IN (SELECT TOP %d %s",
 		column, statement.Start, column); err != nil {
-				return "", nil, err
+		return err
 	}
-			if err := statement.writeFrom(mssqlCondi); err != nil {
+	if err := statement.writeFrom(subWriter); err != nil {
-				return "", nil, err
+		return err
 	}
-			if whereStr != "" {
+	if statement.cond.IsValid() {
-				if _, err := fmt.Fprint(mssqlCondi, whereStr); err != nil {
+		if _, err := fmt.Fprint(subWriter, " WHERE "); err != nil {
-					return "", nil, err
+			return err
 		}
-				if err := utils.WriteBuilder(mssqlCondi, statement.QuoteReplacer(condWriter)); err != nil {
+		if err := statement.cond.WriteTo(statement.QuoteReplacer(subWriter)); err != nil {
-					return "", nil, err
+			return err
 		}
 	}
-			if needOrderBy {
+	if err := statement.WriteOrderBy(subWriter); err != nil {
-				if err := statement.WriteOrderBy(mssqlCondi); err != nil {
+		return err
-					return "", nil, err
-				}
-			}
-			if err := statement.writeGroupBy(mssqlCondi); err != nil {
-				return "", nil, err
-			}
-			if _, err := fmt.Fprint(mssqlCondi, "))"); err != nil {
-				return "", nil, err
 	}
+	if err := statement.writeGroupBy(subWriter); err != nil {
+		return err
 	}
+	if _, err := fmt.Fprint(subWriter, "))"); err != nil {
+		return err
 	}
 
-	buf := builder.NewWriter()
+	if statement.cond.IsValid() {
-	if _, err := fmt.Fprintf(buf, "SELECT %v%v%v", distinct, top, columnStr); err != nil {
+		if _, err := fmt.Fprint(w, " AND "); err != nil {
-		return "", nil, err
+			return err
-	}
-	if err := statement.writeFrom(buf); err != nil {
-		return "", nil, err
-	}
-	if whereStr != "" {
-		if _, err := fmt.Fprint(buf, whereStr); err != nil {
-			return "", nil, err
-		}
-		if err := utils.WriteBuilder(buf, statement.QuoteReplacer(condWriter)); err != nil {
-			return "", nil, err
-		}
-	}
-	if mssqlCondi.Len() > 0 {
-		if len(whereStr) > 0 {
-			if _, err := fmt.Fprint(buf, " AND "); err != nil {
-				return "", nil, err
 		}
 	} else {
-			if _, err := fmt.Fprint(buf, " WHERE "); err != nil {
+		if _, err := fmt.Fprint(w, " WHERE "); err != nil {
-				return "", nil, err
+			return err
 		}
 	}
 
-		if err := utils.WriteBuilder(buf, mssqlCondi); err != nil {
+	return utils.WriteBuilder(w, subWriter)
-			return "", nil, err
+}
-		}
+
+func (statement *Statement) writeOracleLimit(w *builder.BytesWriter, columnStr string) error {
+	if statement.LimitN == nil {
+		return nil
 	}
 
-	if err := statement.writeGroupBy(buf); err != nil {
+	oldString := w.String()
-		return "", nil, err
+	w.Reset()
-	}
-	if err := statement.writeHaving(buf); err != nil {
-		return "", nil, err
-	}
-	if needOrderBy {
-		if err := statement.WriteOrderBy(buf); err != nil {
-			return "", nil, err
-		}
-	}
-	if needLimit {
-		if dialect.URI().DBType != schemas.MSSQL && dialect.URI().DBType != schemas.ORACLE {
-			if err := statement.writeLimitOffset(buf); err != nil {
-				return "", nil, err
-			}
-		} else if dialect.URI().DBType == schemas.ORACLE {
-			if pLimitN != nil {
-				oldString := buf.String()
-				buf.Reset()
 	rawColStr := columnStr
 	if rawColStr == "*" {
 		rawColStr = "at.*"
 	}
-				fmt.Fprintf(buf, "SELECT %v FROM (SELECT %v,ROWNUM RN FROM (%v) at WHERE ROWNUM <= %d) aat WHERE RN > %d",
+	_, err := fmt.Fprintf(w, "SELECT %v FROM (SELECT %v,ROWNUM RN FROM (%v) at WHERE ROWNUM <= %d) aat WHERE RN > %d",
-					columnStr, rawColStr, oldString, statement.Start+*pLimitN, statement.Start)
+		columnStr, rawColStr, oldString, statement.Start+*statement.LimitN, statement.Start)
+	return err
+}
+
+func (statement *Statement) writeSelect(buf *builder.BytesWriter, columnStr string, needLimit bool) error {
+	if err := statement.writeSelectColumns(buf, columnStr); err != nil {
+		return err
 	}
+	if err := statement.writeFrom(buf); err != nil {
+		return err
 	}
+	if err := statement.writeWhere(buf); err != nil {
+		return err
 	}
-	if statement.IsForUpdate {
+	if err := statement.writeGroupBy(buf); err != nil {
-		return dialect.ForUpdateSQL(buf.String()), buf.Args(), nil
+		return err
+	}
+	if err := statement.writeHaving(buf); err != nil {
+		return err
+	}
+	if err := statement.WriteOrderBy(buf); err != nil {
+		return err
 	}
 
-	return buf.String(), buf.Args(), nil
+	dialect := statement.dialect
+	if needLimit {
+		if dialect.URI().DBType == schemas.ORACLE {
+			if err := statement.writeOracleLimit(buf, columnStr); err != nil {
+				return err
+			}
+		} else if dialect.URI().DBType != schemas.MSSQL {
+			if err := statement.writeLimitOffset(buf); err != nil {
+				return err
+			}
+		}
+	}
+	return statement.writeForUpdate(buf)
 }
 
 // GenExistSQL generates Exist SQL
@@ -457,6 +479,33 @@ func (statement *Statement) GenExistSQL(bean ...interface{}) (string, []interfac
 	return buf.String(), buf.Args(), nil
 }
 
+func (statement *Statement) genSelectColumnStr() string {
+	// manually select columns
+	if len(statement.SelectStr) > 0 {
+		return statement.SelectStr
+	}
+
+	columnStr := statement.ColumnStr()
+	if columnStr != "" {
+		return columnStr
+	}
+
+	// autodetect columns
+	if statement.GroupByStr != "" {
+		return statement.quoteColumnStr(statement.GroupByStr)
+	}
+
+	if len(statement.joins) != 0 {
+		return "*"
+	}
+
+	columnStr = statement.genColumnStr()
+	if columnStr == "" {
+		columnStr = "*"
+	}
+	return columnStr
+}
+
 // GenFindSQL generates Find SQL
 func (statement *Statement) GenFindSQL(autoCond builder.Cond) (string, []interface{}, error) {
 	if statement.RawSQL != "" {
@@ -467,33 +516,11 @@ func (statement *Statement) GenFindSQL(autoCond builder.Cond) (string, []interfa
 		return "", nil, ErrTableNotFound
 	}
 
-	columnStr := statement.ColumnStr()
-	if len(statement.SelectStr) > 0 {
-		columnStr = statement.SelectStr
-	} else {
-		if len(statement.joins) == 0 {
-			if columnStr == "" {
-				if statement.GroupByStr != "" {
-					columnStr = statement.quoteColumnStr(statement.GroupByStr)
-				} else {
-					columnStr = statement.genColumnStr()
-				}
-			}
-		} else {
-			if columnStr == "" {
-				if statement.GroupByStr != "" {
-					columnStr = statement.quoteColumnStr(statement.GroupByStr)
-				} else {
-					columnStr = "*"
-				}
-			}
-		}
-		if columnStr == "" {
-			columnStr = "*"
-		}
-	}
-
 	statement.cond = statement.cond.And(autoCond)
 
-	return statement.genSelectSQL(columnStr, true, true)
+	buf := builder.NewWriter()
+	if err := statement.writeSelect(buf, statement.genSelectColumnStr(), true); err != nil {
+		return "", nil, err
+	}
+	return buf.String(), buf.Args(), nil
 }

internal/statements/update.go

@@ -19,7 +19,8 @@ import (
 )
 
 func (statement *Statement) ifAddColUpdate(col *schemas.Column, includeVersion, includeUpdated, includeNil,
-	includeAutoIncr, update bool) (bool, error) {
+	includeAutoIncr, update bool,
+) (bool, error) {
 	columnMap := statement.ColumnMap
 	omitColumnMap := statement.OmitColumnMap
 	unscoped := statement.unscoped
@@ -64,15 +65,16 @@ func (statement *Statement) ifAddColUpdate(col *schemas.Column, includeVersion,
 // BuildUpdates auto generating update columnes and values according a struct
 func (statement *Statement) BuildUpdates(tableValue reflect.Value,
 	includeVersion, includeUpdated, includeNil,
-	includeAutoIncr, update bool) ([]string, []interface{}, error) {
+	includeAutoIncr, update bool,
+) ([]string, []interface{}, error) {
 	table := statement.RefTable
 	allUseBool := statement.allUseBool
 	useAllCols := statement.useAllCols
 	mustColumnMap := statement.MustColumnMap
 	nullableMap := statement.NullableMap
 
-	var colNames = make([]string, 0)
+	colNames := make([]string, 0)
-	var args = make([]interface{}, 0)
+	args := make([]interface{}, 0)
 
 	for _, col := range table.Columns() {
 		ok, err := statement.ifAddColUpdate(col, includeVersion, includeUpdated, includeNil,