Add view support (#4459)

add view support in MO

Approved by: @fengttt, @iamlinjunhong, @aunjgr, @daviszhen, @nnsgmsone, @XuPeng-SH, @reusee, @aressu1985

pkg/vm/engine/types.go

@@ -109,11 +109,16 @@ type CommentDef struct {
 	Comment string
 }
 
+type ViewDef struct {
+	View string
+}
+
 type TableDef interface {
 	tableDef()
 }
 
 func (*CommentDef) tableDef()      {}
+func (*ViewDef) tableDef()         {}
 func (*AttributeDef) tableDef()    {}
 func (*IndexTableDef) tableDef()   {}
 func (*PropertiesDef) tableDef()   {}

proto/plan.proto

@@ -218,12 +218,17 @@ message PropertiesDef {
 	repeated Property properties 	= 1;
 }
 
+message ViewDef {
+	string view  = 1;
+}
+
 message TableDef {
 	message DefType {
 		oneof def {
 			PrimaryKeyDef pk			= 1;
 			IndexDef idx				= 2;
 			PropertiesDef properties	= 3;
+			ViewDef view				= 4;
 		}
 	}
 	string name				= 1;

test/cases/view/view.test

+-- @label:bvt
+drop table if exists t1;
+create table t1 (a int, b int);
+create view v1 as select * from t1;
+select * from v1;
+insert into t1 values (1, 11), (2, 22), (3, 33);
+show columns from v1;
+select * from v1 where a > 1;
+create database db2;
+use db2;
+select * from view.v1 where a > 1;
+use view;
+drop database db2;
+drop table t1;
+select * from v1;
+drop table v1;
+drop view v1;
\ No newline at end of file

test/result/view/view.result

+drop table if exists t1;
+create table t1 (a int, b int);
+create view v1 as select * from t1;
+select * from v1;
+a	b
+insert into t1 values (1, 11), (2, 22), (3, 33);
+show columns from v1;
+Field	Type	Null	Key	Default	Comment
+a	INT	YES		NULL	
+b	INT	YES		NULL
+select * from v1 where a > 1;
+a	b
+2	22
+3	33
+create database db2;
+use db2;
+select * from view.v1 where a > 1;
+a	b
+2	22
+3	33
+use view;
+drop database db2;
+drop table t1;
+select * from v1;
+table "t1" does not exist
+drop table v1;
+table v1 is not exists
+drop view v1;
\ No newline at end of file