Fix mssql issue with duplicate columns. (#1225)

fix test

fix test

Fix mssql issue with duplicate columns.

The `GetColumns()` method for the mssql dialect can return the same
column multiple times if the column is in multiple indexes.

Co-authored-by: Robert G. Jakabosky <bobby@sharedrealm.com>
Reviewed-on: https://gitea.com/xorm/xorm/pulls/1225

dialects/mssql.go

@@ -335,14 +335,15 @@ func (db *mssql) GetColumns(ctx context.Context, tableName string) ([]string, ma
 	s := `select a.name as name, b.name as ctype,a.max_length,a.precision,a.scale,a.is_nullable as nullable,
 		  "default_is_null" = (CASE WHEN c.text is null THEN 1 ELSE 0 END),
 	      replace(replace(isnull(c.text,''),'(',''),')','') as vdefault,
-		  ISNULL(i.is_primary_key, 0), a.is_identity as is_identity
+		  ISNULL(p.is_primary_key, 0), a.is_identity as is_identity
           from sys.columns a 
 		  left join sys.types b on a.user_type_id=b.user_type_id
           left join sys.syscomments c on a.default_object_id=c.id
-		  LEFT OUTER JOIN 
-    sys.index_columns ic ON ic.object_id = a.object_id AND ic.column_id = a.column_id
-		  LEFT OUTER JOIN 
-    sys.indexes i ON ic.object_id = i.object_id AND ic.index_id = i.index_id
+		  LEFT OUTER JOIN (SELECT i.object_id, ic.column_id, i.is_primary_key
+			FROM sys.indexes i
+		  LEFT JOIN sys.index_columns ic ON ic.object_id = i.object_id AND ic.index_id = i.index_id
+			WHERE i.is_primary_key = 1
+		) as p on p.object_id = a.object_id AND p.column_id = a.column_id
           where a.object_id=object_id('` + tableName + `')`
 
 	rows, err := db.DB().QueryContext(ctx, s, args...)

tags_test.go

@@ -6,6 +6,7 @@ package xorm
 
 import (
 	"fmt"
+	"sort"
 	"strings"
 	"testing"
 	"time"
@@ -1295,3 +1296,34 @@ func TestVersion4(t *testing.T) {
 		assert.EqualValues(t, v.Ver, 1)
 	}
 }
+
+func TestIndexes(t *testing.T) {
+	assert.NoError(t, prepareEngine())
+
+	type TestIndexesStruct struct {
+		Id    int64
+		Name  string `xorm:"index unique(s)"`
+		Email string `xorm:"index unique(s)"`
+	}
+
+	assertSync(t, new(TestIndexesStruct))
+
+	tables, err := testEngine.DBMetas()
+	assert.NoError(t, err)
+	assert.EqualValues(t, 1, len(tables))
+	assert.EqualValues(t, 3, len(tables[0].Columns()))
+	slice1 := []string{
+		testEngine.GetColumnMapper().Obj2Table("Id"),
+		testEngine.GetColumnMapper().Obj2Table("Name"),
+		testEngine.GetColumnMapper().Obj2Table("Email"),
+	}
+	slice2 := []string{
+		tables[0].Columns()[0].Name,
+		tables[0].Columns()[1].Name,
+		tables[0].Columns()[2].Name,
+	}
+	sort.Strings(slice1)
+	sort.Strings(slice2)
+	assert.EqualValues(t, slice1, slice2)
+	assert.EqualValues(t, 3, len(tables[0].Indexes))
+}