CREATE[UNIQUE]INDEX[CONCURRENTLY][[IFNOTEXISTS]name]ON[ONLY]table_name[USINGmethod]({column_name|(expression)}[COLLATEcollation][opclass[(opclass_parameter=value[,...])]][ASC|DESC][NULLS{FIRST|LAST}][,...])[INCLUDE(column_name[,...])][WITH(storage_parameter[=value][,...])][TABLESP...
4.创建索引 --建普通索引(索引名通常为 idx_表名_字段名)CREATEINDEXIFNOTEXISTSidx_my_table_ageONmy_table USING btree (age);--建唯一索引CREATEUNIQUEINDEXCONCURRENTLYIFNOTEXISTSidx_unique_my_table_idONmy_table (id);--组合索引CREATEINDEXIFNOTEXISTSindex_nameONtable_name (column1_name, column2_nam...
CREATE UNIQUE INDEX ind_t_id_1 on t (id); 2. 关键字【CONCURRENTLY】 # 这是并发创建索引。跟oracle的online创建索引作用是一样的。创建索引过程中;不会阻塞表更新,插入,删除操作。当然创建的时间就会很漫长。 CREATE INDEX CONCURRENTLY ind_t_id_2 on t (id); 3. 关键字【IF NOT EXISTS】 #用该...
CREATEMATERIALIZEDVIEW[IFNOTEXISTS]nameASquery[WITH[NO]DATA]; 其中,IF NOT EXISTS 可以避免重复创建一个已经存在的物化视图时产生错误;name 是物化视图的名称;query 是物化视图的查询语句。 WITH DATA 表示创建时填充物化视图中的数据,这个是默认选项;WITH NO DATA 表示创建时不填充数据,此时无法查询物化视图中的...
ADD table_constraint [ NOT VALID ] ADD table_constraint_using_index ALTER CONSTRAINT constraint_name [ DEFERRABLE | NOT DEFERRABLE ] [ INITIALLY DEFERRED | INITIALLY IMMEDIATE ] VALIDATE CONSTRAINT constraint_name DROP CONSTRAINT [ IF EXISTS ] constraint_name [ RESTRICT | CASCADE ] ...
---address_pkey | CREATE UNIQUE INDEX address_pkey ON public.address USING btree (address_id)idx_fk_city_id | CREATE INDEX idx_fk_city_id ON public.address USING btree (city_id)idx_address_phone | CREATE INDEX idx_address_phone ON public.address USING btree (phone)(3 rows) The output...
create unique index 索引名 on 表名(列名1,列名2...);六、基于表达式的索引: create index 索引名 on 表名(表达式);create index inx_title on film(lower(title));七、局部索引: create index 索引名 on 表名(列名)wherecondition;create index inx_title on film(title)wheretitle like'Cu%';八、重新...
CREATE[ UNIQUE ]INDEX[ CONCURRENTLY ] [ [IFNOTEXISTS ] name ]ONtable_name [USINGmethod]( { column_name | ( expression )} [COLLATEcollation] [opclass] [ASC|DESC] [NULLS{ FIRST | LAST }] [, ...] ) [WITH( storage_parameter = value [, ... ] )] ...
在Postgres中,可以使用done ()或lcase()来完成: CREATE UNIQUE INDEX lower_username_index ON enduser_table ((lcase(name))); PostgreSQL也有CITEXT数据类型,但不幸的是,HSQL似乎不支持它。我目前的版本是HSQL2.2.8和PostgreSQL 9.0.5。或者,其他内存中的数据库可能更适合测试SQL和PostgreSQL?提前感谢! 浏览1...
Introduction to PostgreSQL UNIQUE index The PostgreSQL unique index enforces the uniqueness of values in one or multiple columns. To create a unique index, you use the followingCREATE UNIQUE INDEXstatement: CREATEUNIQUEINDEXindex_nameONtable_name(column [,...])[ NULLS [ NOT ] DISTINCT ]; ...