[Feature Request]: Implement information_schema.table_constraints

[fengttt]

Is there an existing issue for the same feature request?

• I have checked the existing issues.

Is your feature request related to a problem?

Right now information_schema.table_constraints is a table, no data. 


	InformationSchemaTableConstraintsDDL = "CREATE TABLE information_schema.TABLE_CONSTRAINTS (" +
		"CONSTRAINT_CATALOG varchar(64)," +
		"CONSTRAINT_SCHEMA varchar(64)," +
		"CONSTRAINT_NAME varchar(64)," +
		"TABLE_SCHEMA varchar(64)," +
		"TABLE_NAME varchar(64)," +
		"CONSTRAINT_TYPE varchar(11) NOT NULL DEFAULT ''," +
		"ENFORCED varchar(3) NOT NULL DEFAULT ''" +
		")"


This implementation is essentially wrong.   EVERYTHING in information_schema should be a view.   So the implementation should be like the following, 


InformationSchemaReferentialConstraintsDDL = "CREATE VIEW information_schema.REFERENTIAL_CONSTRAINTS AS " +
		"SELECT DISTINCT " +
		"'def' AS CONSTRAINT_CATALOG, " +
		"fk.db_name AS CONSTRAINT_SCHEMA, " +
		"fk.constraint_name AS CONSTRAINT_NAME, " +
		"'def' AS UNIQUE_CONSTRAINT_CATALOG, " +
		"fk.refer_db_name AS UNIQUE_CONSTRAINT_SCHEMA, " +
		"idx.type AS UNIQUE_CONSTRAINT_NAME," +
		"'NONE' AS MATCH_OPTION, " +
		"fk.on_update AS UPDATE_RULE, " +
		"fk.on_delete AS DELETE_RULE, " +
		"fk.table_name AS TABLE_NAME, " +
		"fk.refer_table_name AS REFERENCED_TABLE_NAME " +
		"FROM mo_catalog.mo_foreign_keys fk " +
		"JOIN mo_catalog.mo_indexes idx ON (fk.refer_column_name = idx.column_name)"

Describe the feature you'd like

Seems mo_catalog.mo_indexes has everything you need, so just a view on it should probably be fine.

There needs to be an upgrade step.

Describe implementation you've considered

No response

Documentation, Adoption, Use Case, Migration Strategy

Additional information

No response

[volgariver6]

经讨论，该问题尽快处理，进2.0.2版本

[ck89119]

working on it

[heni02]

相关联的bug已验证，confrim,closed