fix forgot removed records when deleting user (#5429)

* fix forgot removed records when deleting user

* fix migration

* fix rewritekey lock on sqlite

* remove unused codes

vendor/github.com/go-xorm/builder/builder_limit.go

@@ -0,0 +1,100 @@
+// Copyright 2018 The Xorm Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package builder
+
+import (
+	"fmt"
+	"strings"
+)
+
+func (b *Builder) limitWriteTo(w Writer) error {
+	if strings.TrimSpace(b.dialect) == "" {
+		return ErrDialectNotSetUp
+	}
+
+	if b.limitation != nil {
+		limit := b.limitation
+		if limit.offset < 0 || limit.limitN <= 0 {
+			return ErrInvalidLimitation
+		}
+		// erase limit condition
+		b.limitation = nil
+		ow := w.(*BytesWriter)
+
+		switch strings.ToLower(strings.TrimSpace(b.dialect)) {
+		case ORACLE:
+			if len(b.selects) == 0 {
+				b.selects = append(b.selects, "*")
+			}
+
+			var final *Builder
+			selects := b.selects
+			b.selects = append(selects, "ROWNUM RN")
+
+			var wb *Builder
+			if b.optype == unionType {
+				wb = Dialect(b.dialect).Select("at.*", "ROWNUM RN").
+					From(b, "at")
+			} else {
+				wb = b
+			}
+
+			if limit.offset == 0 {
+				final = Dialect(b.dialect).Select(selects...).From(wb, "at").
+					Where(Lte{"at.RN": limit.limitN})
+			} else {
+				sub := Dialect(b.dialect).Select("*").
+					From(b, "at").Where(Lte{"at.RN": limit.offset + limit.limitN})
+
+				final = Dialect(b.dialect).Select(selects...).From(sub, "att").
+					Where(Gt{"att.RN": limit.offset})
+			}
+
+			return final.WriteTo(ow)
+		case SQLITE, MYSQL, POSTGRES:
+			// if type UNION, we need to write previous content back to current writer
+			if b.optype == unionType {
+				if err := b.WriteTo(ow); err != nil {
+					return err
+				}
+			}
+
+			if limit.offset == 0 {
+				fmt.Fprint(ow, " LIMIT ", limit.limitN)
+			} else {
+				fmt.Fprintf(ow, " LIMIT %v OFFSET %v", limit.limitN, limit.offset)
+			}
+		case MSSQL:
+			if len(b.selects) == 0 {
+				b.selects = append(b.selects, "*")
+			}
+
+			var final *Builder
+			selects := b.selects
+			b.selects = append(append([]string{fmt.Sprintf("TOP %d %v", limit.limitN+limit.offset, b.selects[0])},
+				b.selects[1:]...), "ROW_NUMBER() OVER (ORDER BY (SELECT 1)) AS RN")
+
+			var wb *Builder
+			if b.optype == unionType {
+				wb = Dialect(b.dialect).Select("*", "ROW_NUMBER() OVER (ORDER BY (SELECT 1)) AS RN").
+					From(b, "at")
+			} else {
+				wb = b
+			}
+
+			if limit.offset == 0 {
+				final = Dialect(b.dialect).Select(selects...).From(wb, "at")
+			} else {
+				final = Dialect(b.dialect).Select(selects...).From(wb, "at").Where(Gt{"at.RN": limit.offset})
+			}
+
+			return final.WriteTo(ow)
+		default:
+			return ErrNotSupportType
+		}
+	}
+
+	return nil
+}