pingcap#22316 add a function tryFillViewColumnType, so we can reuse it.

beihaiguaishou · Jan 12, 2021 · b041a85 · b041a85
1 parent 11494cd
commit b041a85
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Showing 2 changed files with 31 additions and 40 deletions.
diff --git a/executor/infoschema_reader.go b/executor/infoschema_reader.go
@@ -35,7 +35,6 @@ 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"
@@ -51,7 +50,6 @@ 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"
@@ -568,25 +566,9 @@ func (e *hugeMemTableRetriever) setDataForColumns(ctx context.Context, sctx sess
 }
 
 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
- }
+ if err := tryFillViewColumnType(ctx, sctx, infoschema.GetInfoSchema(sctx), schema.Name, tbl); err != nil {
+ sctx.GetSessionVars().StmtCtx.AppendWarning(err)
+ return
  }
  for i, col := range tbl.Columns {
  if col.Hidden {

diff --git a/executor/show.go b/executor/show.go
@@ -459,25 +459,8 @@ func (e *ShowExec) fetchShowColumns(ctx context.Context) error {
  } else {
  cols = tb.VisibleCols()
  }
- if tb.Meta().IsView() {
- // Because view's undertable's column could change or recreate, so view's column type may change overtime.
- // To avoid this situation we need to generate a logical plan and extract current column types from Schema.
- planBuilder, _ := plannercore.NewPlanBuilder(e.ctx, e.is, &hint.BlockHintProcessor{})
- viewLogicalPlan, err := planBuilder.BuildDataSourceFromView(ctx, e.DBName, tb.Meta())
- if err != nil {
- return err
- }
- viewSchema := viewLogicalPlan.Schema()
- viewOutputNames := viewLogicalPlan.OutputNames()
- for _, col := range cols {
- 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
- }
- }
+ if err := tryFillViewColumnType(ctx, e.ctx, e.is, e.DBName, tb.Meta()); err != nil {
+ return err
  }
  for _, col := range cols {
  if e.Column != nil && e.Column.Name.L != col.Name.L {
@@ -1645,3 +1628,29 @@ func (e *ShowExec) fetchShowBuiltins() error {
  }
  return nil
 }
+
+// tryFillViewColumnType fill the columns type info of a view.
+// Because view's underlying table's column could change or recreate, so view's column type may change over time.
+// To avoid this situation we need to generate a logical plan and extract current column types from Schema.
+func tryFillViewColumnType(ctx context.Context, sctx sessionctx.Context, is infoschema.InfoSchema, dbName model.CIStr, tbl *model.TableInfo) error {
+ if tbl.IsView() {
+ // Retrieve view columns info.
+ planBuilder, _ := plannercore.NewPlanBuilder(sctx, is, &hint.BlockHintProcessor{})
+ if viewLogicalPlan, err := planBuilder.BuildDataSourceFromView(ctx, dbName, 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 {
+ return err
+ }
+ }
+ return nil
+}