MsSQL Limits

builder.go

@@ -358,20 +358,13 @@ func (b *Builder) ToSQL() (string, []interface{}, error) {
 	var err error
 
 	switch b.dialect {
-	case ORACLE, MSSQL:
+	case ORACLE:
 		// This is for compatibility with different sql drivers
 		for e := range w.args {
 			w.args[e] = sql2.Named(fmt.Sprintf("p%d", e+1), w.args[e])
 		}
 
-		var prefix string
-		if b.dialect == ORACLE {
-			prefix = ":p"
-		} else {
-			prefix = "@p"
-		}
-
-		if sql, err = ConvertPlaceholder(sql, prefix); err != nil {
+		if sql, err = ConvertPlaceholder(sql, ":p"); err != nil {
 			return "", nil, err
 		}
 	case POSTGRES:

builder_limit.go

@@ -67,30 +67,7 @@ func (b *Builder) limitWriteTo(w Writer) error {
 				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)
+			fmt.Fprintf(ow, " OFFSET %v ROWS FETCH NEXT %v ROWS ONLY", limit.offset, limit.limitN)
 		default:
 			return ErrNotSupportType
 		}

builder_select.go

@@ -21,7 +21,7 @@ func (b *Builder) selectWriteTo(w Writer) error {
 
 	// perform limit before writing to writer when b.dialect between ORACLE and MSSQL
 	// this avoid a duplicate writing problem in simple limit query
-	if b.limitation != nil && (b.dialect == ORACLE || b.dialect == MSSQL) {
+	if b.limitation != nil && b.dialect == ORACLE {
 		return b.limitWriteTo(w)
 	}
 
@@ -115,6 +115,17 @@ func (b *Builder) selectWriteTo(w Writer) error {
 		if _, err := fmt.Fprint(w, " ORDER BY ", b.orderBy); err != nil {
 			return err
 		}
+
+		if b.limitation != nil && b.dialect == MSSQL {
+			if err := b.limitWriteTo(w); err != nil {
+				return err
+			}
+		}
+	}
+
+	// limit can only appear after an order by clause
+	if b.limitation != nil && b.dialect == MSSQL {
+		return ErrInvalidLimitation
 	}
 
 	if b.limitation != nil {