fix can not show view data_type pingcap#22316

executor/infoschema_reader.go

@@ -35,6 +35,7 @@ import (
 	"github.com/pingcap/tidb/ddl/placement"
 	"github.com/pingcap/tidb/domain"
 	"github.com/pingcap/tidb/domain/infosync"
+	"github.com/pingcap/tidb/expression"
 	"github.com/pingcap/tidb/infoschema"
 	"github.com/pingcap/tidb/meta/autoid"
 	plannercore "github.com/pingcap/tidb/planner/core"
@@ -50,6 +51,7 @@ import (
 	"github.com/pingcap/tidb/util"
 	"github.com/pingcap/tidb/util/chunk"
 	"github.com/pingcap/tidb/util/collate"
+	"github.com/pingcap/tidb/util/hint"
 	"github.com/pingcap/tidb/util/pdapi"
 	"github.com/pingcap/tidb/util/set"
 	"github.com/pingcap/tidb/util/sqlexec"
@@ -542,20 +544,20 @@ func (e *memtableRetriever) setDataFromTables(ctx sessionctx.Context, schemas []
 	return nil
 }
 
-func (e *hugeMemTableRetriever) setDataForColumns(ctx sessionctx.Context) error {
-	checker := privilege.GetPrivilegeManager(ctx)
+func (e *hugeMemTableRetriever) setDataForColumns(ctx context.Context, sctx sessionctx.Context) error {
+	checker := privilege.GetPrivilegeManager(sctx)
 	e.rows = e.rows[:0]
 	batch := 1024
 	for ; e.dbsIdx < len(e.dbs); e.dbsIdx++ {
 		schema := e.dbs[e.dbsIdx]
 		for e.tblIdx < len(schema.Tables) {
 			table := schema.Tables[e.tblIdx]
 			e.tblIdx++
-			if checker != nil && !checker.RequestVerification(ctx.GetSessionVars().ActiveRoles, schema.Name.L, table.Name.L, "", mysql.AllPrivMask) {
+			if checker != nil && !checker.RequestVerification(sctx.GetSessionVars().ActiveRoles, schema.Name.L, table.Name.L, "", mysql.AllPrivMask) {
 				continue
 			}
 
-			e.dataForColumnsInTable(schema, table)
+			e.dataForColumnsInTable(ctx, sctx, schema, table)
 			if len(e.rows) >= batch {
 				return nil
 			}
@@ -565,7 +567,27 @@ func (e *hugeMemTableRetriever) setDataForColumns(ctx sessionctx.Context) error
 	return nil
 }
 
-func (e *hugeMemTableRetriever) dataForColumnsInTable(schema *model.DBInfo, tbl *model.TableInfo) {
+func (e *hugeMemTableRetriever) dataForColumnsInTable(ctx context.Context, sctx sessionctx.Context, schema *model.DBInfo, tbl *model.TableInfo) {
+	if tbl.IsView() {
+		// retrieve view columns info
+		planBuilder, _ := plannercore.NewPlanBuilder(sctx, infoschema.GetInfoSchema(sctx), &hint.BlockHintProcessor{})
+		if viewLogicalPlan, err := planBuilder.BuildDataSourceFromView(ctx, schema.Name, tbl); err == nil {
+			viewSchema := viewLogicalPlan.Schema()
+			viewOutputNames := viewLogicalPlan.OutputNames()
+			for _, col := range tbl.Columns {
+				idx := expression.FindFieldNameIdxByColName(viewOutputNames, col.Name.L)
+				if idx >= 0 {
+					col.FieldType = *viewSchema.Columns[idx].GetType()
+				}
+				if col.Tp == mysql.TypeVarString {
+					col.Tp = mysql.TypeVarchar
+				}
+			}
+		} else {
+			sctx.GetSessionVars().StmtCtx.AppendWarning(err)
+			return
+		}
+	}
 	for i, col := range tbl.Columns {
 		if col.Hidden {
 			continue
@@ -1891,7 +1913,7 @@ func (e *hugeMemTableRetriever) retrieve(ctx context.Context, sctx sessionctx.Co
 	var err error
 	switch e.table.Name.O {
 	case infoschema.TableColumns:
-		err = e.setDataForColumns(sctx)
+		err = e.setDataForColumns(ctx, sctx)
 	}
 	if err != nil {
 		return nil, err