Gbase 8C - SQL reference 6 SQL syntax (9)

1. DROP DOMAIN

Function description

Remove a domain .

Grammar format

DROP DOMAIN [ IF EXISTS ] name [, ...] [ CASCADE | RESTRICT ]

Parameter description

1. IF EXISTS： If the domain does not exist , No error, just prompt ;
2. name： Name of existing domain , Can be modified by patterns ;

1. CASCADE： Automatically delete objects that depend on this domain （ Such as table ）, And all objects that depend on those objects ;

1. RESTRICT： If any object depends on this domain , Then refuse to delete , This is the default setting .

matters needing attention

Only the owner of the domain can remove the domain .

Example

DROP DOMAIN us_postal_code;

DROP DOMAIN

Grammar compatible

except IF EXISTS Options , This command conforms to SQL standard .IF EXISTS It's a PostgreSQL Expand .

Related to the grammar

CREATE DOMAIN, ALTER DOMAIN

1. DROP EXTENSION

Function description

Remove an extension .

Grammar format

DROP EXTENSION [ IF EXISTS ] name [, ...] [ CASCADE | RESTRICT ]

Parameter description

1. IF EXISTS： If the extension does not exist , No error, just prompt ;
2. name： The name of the installed extension ;

1. CASCADE： Automatically delete objects that depend on this extension , And all objects that depend on those objects ;

1. RESTRICT： If any object depends on that object , Then refuse to delete , This is the default setting .

matters needing attention

Only the owner of the extension can remove the extension .

Example

DROP EXTENSION hstore;

DROP EXTENSION

Grammar compatible

DROP EXTENSION It's a PostgreSQL Expand .

Related to the grammar

CREATE EXTENSION, ALTER EXTENSION

1. DROP FUNCTION

Function description

Delete a function .

Grammar format

DROP FUNCTION [ IF EXISTS ] name [ ( [ [ argmode ] [ argname ] argtype [, ...] ] ) ] [, ...]

    [ CASCADE | RESTRICT ]

Parameter description

1. IF EXISTS： If the function doesn't exist , No error, just prompt ;
2. name： Name of existing function , Can be modified by patterns ;
3. argmode： Mode of function parameters , Value range ：IN、OUT、INOUT perhaps VARIADIC, Default is IN;
4. argname： The name of the function parameter , Value range ： character string ;
5. argtype： The data type of the function parameter ;

1. CASCADE： Automatically delete objects that depend on this function （ Such as operators and triggers ）, And all objects that depend on those objects ;

1. RESTRICT： If any object depends on this function , Then refuse to delete , This is the default setting .

matters needing attention

Only the owner of the function can remove the function .

The parameter type of the function must be specified , Because different functions may have the same name and different parameter lists .

Example

DROP FUNCTION func_get(integer);

DROP FUNCTION

Grammar compatible

This command complies with SQL standard .

Related to the grammar

CREATE FUNCTION, ALTER FUNCTION

1. DROP GROUP

Function description

Remove a database role .

Grammar format

DROP GROUP [ IF EXISTS ] name [, ...]

Parameter description

Reference resources DROP ROLE Parameter description of .

matters needing attention

DROP GROUP yes DROP ROLE Another name for .

Grammar compatible

stay SQL There is no in the standard DROP GROUP sentence .

Related to the grammar

DROP ROLE

1. DROP INDEX

Function description

Remove an index .

Grammar format

DROP INDEX [ CONCURRENTLY ] [ IF EXISTS ] name [, ...] [ CASCADE | RESTRICT ]

Parameter description

1. CONCURRENTLY： Delete the index without locking . When deleting an index , Generally, other statements will block access to the table that the index depends on . Add this keyword , It can realize that there is no blocking in the deletion process . This option can only specify the name of one index , also CASCADE Option does not support . Ordinary DROP INDEX Commands can be executed within a transaction , however DROP INDEX CONCURRENTLY Cannot execute within a transaction ;
2. IF EXISTS： If the index does not exist , No error, just prompt ;
3. name： The name of the index to be removed , Can be modified by patterns ;

1. CASCADE： Automatically delete objects that depend on the index , And all objects that depend on those objects ;

1. RESTRICT： If any object depends on the index , Then refuse to delete , This is the default setting .

matters needing attention

Only the owner of the index can remove the index .

Example

DROP INDEX customer_idx;

DROP INDEX

Grammar compatible

DROP INDEX It's a PostgreSQL Language extension . stay SQL Index is not provided in the standard .

Related to the grammar

CREATE INDEX, ALTER INDEX

1. DROP LANGUAGE

Function description

Remove a language .

Grammar format

DROP [ PROCEDURAL ] LANGUAGE [ IF EXISTS ] name [ CASCADE | RESTRICT ]

Parameter description

1. IF EXISTS： If the language does not exist , No error, just prompt ;
2. name： The name of the existing language , You can use single quotation marks ;

1. CASCADE： Automatically delete objects that depend on the index （ For example, functions in this language ）, And all objects that depend on those objects ;

1. RESTRICT： If any object depends on the language , Then refuse to delete , This is the default setting .

matters needing attention

Only the owner of the language can remove the language .

Example

DROP LANGUAGE plsample;

Grammar compatible

stay SQL There is no in the standard DROP LANGUAGE sentence .

Related to the grammar

ALTER LANGUAGE, CREATE LANGUAGE

1. DROP MATERIALIZED VIEW

Function description

Remove a materialized view .

Grammar format

DROP MATERIALIZED VIEW [ IF EXISTS ] name [, ...] [ CASCADE | RESTRICT ]

Parameter description

1. IF EXISTS： If the materialized view does not exist , No error, just prompt ;
2. name： The name of the materialized view to be removed , Can be modified by patterns ;

1. CASCADE： Automatically delete objects that depend on the materialized view （ For example, other materialized views or general views ）, And all objects that depend on those objects ;

1. RESTRICT： If any object depends on the materialized view , Then refuse to delete , This is the default setting .

matters needing attention

Only the owner of the materialized view can remove it .

Example

DROP MATERIALIZED VIEW mv_customer;

DROP MATERIALIZED VIEW

Grammar compatible

DROP MATERIALIZED VIEW It's a PostgreSQL Expand .

Related to the grammar

CREATE MATERIALIZED VIEW, ALTER MATERIALIZED VIEW, REFRESH MATERIALIZED VIEW

1. DROP NODE

Function description

Remove node . This interface is not recommended for users to use directly , So as not to affect the status of the cluster .

Grammar format

DROP NODE nodename

Parameter description

1. nodename： Name of the node to be deleted .

matters needing attention

DROP NODE It is the internal interface encapsulated by the cluster management tool , Used to realize cluster management . This interface is not recommended for users to use directly , So as not to affect the status of the cluster .

Grammar compatible

DROP NODE Not the standard SQL grammar .

Related to the grammar

CREATE NODE,ALTER NODE

1. DROP NODE GROUP

Function description

Delete node group . This interface is not recommended for users to use directly , So as not to affect the status of the cluster .

Grammar format

DROP NODE GROUP groupname

Parameter description

1. groupname： The node group name to delete .

matters needing attention

DROP NODE GROUP It is the internal interface encapsulated by the cluster management tool , Used to realize cluster management . This interface is not recommended for users to use directly , So as not to affect the status of the cluster .

Grammar compatible

DROP NODE GROUP Not the standard SQL grammar .

Related to the grammar

CREATE NODE GROUP

1. DROP OPERATOR

Function description

Remove an operator .

Grammar format

DROP OPERATOR [ IF EXISTS ] name ( { left_type | NONE } , { right_type | NONE } ) [, ...] [ CASCADE | RESTRICT ]

Parameter description

1. IF EXISTS： If the operator does not exist , No error, just prompt ;
2. name： Name of existing operator , Can be modified by patterns ;
3. left_type： The left operand of this operator （ If there is ） Data type of , By default, it can be written as NONE;
4. right_type： The right operand of this operator （ If there is ） Data type of , By default, it can be written as NONE;

1. CASCADE： Automatically delete objects that depend on this operator （ For example, use its view ）, And all objects that depend on those objects ;

1. RESTRICT： If any object depends on this operator , Then refuse to delete , This is the default setting .

matters needing attention

Only the owner of the operator can delete the operator .

Example

DROP OPERATOR ^ (integer, integer);

Grammar compatible

SQL There is no in the standard DROP OPERATOR sentence .

Related to the grammar

CREATE OPERATOR, ALTER OPERATOR