*: support show full columns radondb#533

src/proxy/query.go

@@ -157,7 +157,7 @@ func (spanner *Spanner) ComQuery(session *driver.Session, query string, bindVari
 				log.Error("proxy.show.create.table[%s].from.session[%v].error:%+v", query, session.ID(), err)
 				status = 1
 			}
-		case sqlparser.ShowColumnsStr:
+		case sqlparser.ShowColumnsStr, sqlparser.ShowFullColumnsStr:
 			if qr, err = spanner.handleShowColumns(session, query, node); err != nil {
 				log.Error("proxy.show.colomns[%s].from.session[%v].error:%+v", query, session.ID(), err)
 				status = 1

src/proxy/show.go

@@ -333,10 +333,10 @@ func (spanner *Spanner) handleShowColumns(session *driver.Session, query string,
 	ast := node
 
 	table := ast.Table.Name.String()
-	database := session.Schema()
-	if !ast.Table.Qualifier.IsEmpty() {
-		database = ast.Table.Qualifier.String()
+	if ast.Table.Qualifier.IsEmpty() {
+		ast.Table.Qualifier = sqlparser.NewTableIdent(session.Schema())
 	}
+	database := ast.Table.Qualifier.String()
 	if database == "" {
 		return nil, sqldb.NewSQLError(sqldb.ER_NO_DB_ERROR)
 	}
@@ -352,8 +352,10 @@ func (spanner *Spanner) handleShowColumns(session *driver.Session, query string,
 	}
 	partTable := parts[0].Table
 	backend := parts[0].Backend
-	rewritten := fmt.Sprintf("SHOW COLUMNS FROM %s.%s", database, partTable)
-	qr, err := spanner.ExecuteOnThisBackend(backend, rewritten)
+	ast.Table.Name = sqlparser.NewTableIdent(partTable)
+	buf := sqlparser.NewTrackedBuffer(nil)
+	ast.Format(buf)
+	qr, err := spanner.ExecuteOnThisBackend(backend, buf.String())
 	if err != nil {
 		return nil, err
 	}

src/proxy/show_test.go

@@ -493,7 +493,6 @@ func TestProxyShowCreateTable(t *testing.T) {
 		},
 	}
 
-
 	r2 := &sqltypes.Result{
 		Fields: []*querypb.Field{
 			{
@@ -744,6 +743,55 @@ func TestProxyShowColumns(t *testing.T) {
 		},
 	}
 
+	r3 := &sqltypes.Result{
+		Fields: []*querypb.Field{
+			{
+				Name: "Field",
+				Type: querypb.Type_VARCHAR,
+			},
+			{
+				Name: "Type",
+				Type: querypb.Type_VARCHAR,
+			},
+			{
+				Name: "Null",
+				Type: querypb.Type_VARCHAR,
+			},
+			{
+				Name: "Key",
+				Type: querypb.Type_VARCHAR,
+			},
+			{
+				Name: "Default",
+				Type: querypb.Type_VARCHAR,
+			},
+			{
+				Name: "Extra",
+				Type: querypb.Type_VARCHAR,
+			},
+			{
+				Name: "Privileges",
+				Type: querypb.Type_VARCHAR,
+			},
+			{
+				Name: "Comment",
+				Type: querypb.Type_VARCHAR,
+			},
+		},
+		Rows: [][]sqltypes.Value{
+			{
+				sqltypes.MakeTrusted(querypb.Type_VARCHAR, []byte("col_a")),
+				sqltypes.MakeTrusted(querypb.Type_VARCHAR, []byte("int(11)")),
+				sqltypes.MakeTrusted(querypb.Type_VARCHAR, []byte("YES")),
+				sqltypes.MakeTrusted(querypb.Type_VARCHAR, []byte("PRI")),
+				sqltypes.MakeTrusted(querypb.Type_VARCHAR, []byte("NULL")),
+				sqltypes.MakeTrusted(querypb.Type_VARCHAR, []byte("NULL")),
+				sqltypes.MakeTrusted(querypb.Type_VARCHAR, []byte("select,insert,update,references")),
+				sqltypes.MakeTrusted(querypb.Type_VARCHAR, []byte("NULL")),
+			},
+		},
+	}
+
 	log := xlog.NewStdLog(xlog.Level(xlog.PANIC))
 	fakedbs, proxy, cleanup := MockProxy(log)
 	defer cleanup()
@@ -755,6 +803,7 @@ func TestProxyShowColumns(t *testing.T) {
 		fakedbs.AddQueryPattern("create .*", &sqltypes.Result{})
 		fakedbs.AddQueryPattern("show create .*", r1)
 		fakedbs.AddQueryPattern("show columns .*", r2)
+		fakedbs.AddQueryPattern("show full columns .*", r3)
 	}
 
 	// create database.
@@ -802,6 +851,19 @@ func TestProxyShowColumns(t *testing.T) {
 		assert.Equal(t, want, got)
 	}
 
+	// show full columns from table
+	{
+		client, err := driver.NewConn("mock", "mock", address, "", "utf8")
+		assert.Nil(t, err)
+		defer client.Close()
+		query := "show full columns from test.t1 where `Key` = 'PRI'"
+		qr, err := client.FetchAll(query, -1)
+		assert.Nil(t, err)
+		want := "[col_a int(11) YES PRI NULL NULL select,insert,update,references NULL]"
+		got := fmt.Sprintf("%+v", qr.Rows[0])
+		assert.Equal(t, want, got)
+	}
+
 	// show columns from table err(database is empty)
 	{
 		client, err := driver.NewConn("mock", "mock", address, "", "utf8")