CREATE [UNIQUE|FULLTEXT] INDEX 索引名称 ON 表名(列名...); 1. 2. 二、 drop 1.删除数据库: drop database db1 1. 2.删除数据库表: drop table table1 1. 3.删除列 : ALTER TABLE product3 DROP 列名; 1. 4.删除视图: DROP VIEW view1 1. 5.删除存储过程/函数: DROP PROCEDURE/function ...
type_name,id,group_name,zhan_ping_type,longitude,latitudefromzc_pingzhan_peopleORDERBYgrid_codeasc 参考文章: https://blog.csdn.net/u010112509/article/details/110140414?spm=1001.2101.3001.6650.1&depth_1-utm_relevant_index=2 https://glory.blog.csdn.net/article/details/80865000?spm=1001.2101.3001.6...
ActiveRecord::StatementInvalid in ManagementController#indexPG::Error: ERROR: column "estates.id" must appear in the GROUP BY clause or be used in an aggregate function LINE 1: SELECT "estates".* FROM "estates" WHERE "estates"."Mgmt" = ... ^ : SELECT "estates".* FROM "estates" WHERE ...
3)添加INDEX(普通索引) ALTER TABLE `table_name` ADD INDEX index_name (`column` ) 1. 4)添加FULLTEXT(全文索引) ALTER TABLE `table_name` ADD FULLTEXT (`column`) 1. 5)添加多列索引 ALTER TABLE `table_name` ADD INDEX index_name (`column1`,`column2`,`column3`) 1. 三、索引底层数据结...
Index Cond: (b = 'aa'::text) (2 rows) 真不错,看似一小步,实则是一大步!在德哥的吐槽大会上,有一期[5]也是吐槽优化器的,有一段内容如下: VACUUM autovacuum_vacuum_max_threshold 新增了一个 autovacuum_vacuum_max_threshold 参数,PostgreSQL 默认使用 autovacuum_vacuum_threshold 和 autovacuum_vacuum_sca...
ERROR: column "course.language_id" must appear in the GROUP BY clause or be used in an aggregate function 此时我们可以考虑使用 partition by 来解决这个问题。 除此之外,我们使用使用 order by 时,如果列字段不存在于 group by 子语句中,也会提示上述报错。
ALTER GROUP 修改一个用户组。 ALTERGROUPgroupnameADDUSERusername[,...]ALTERGROUPgroupnameDROPUSERusername[,...]ALTERGROUPgroupnameRENAMETOnew_name 复制 ALTER INDEX 修改一个索引的定义。 ALTERINDEXnameOWNERTOnew_ownerALTERINDEXnameSETTABLESPACEindexspace_nameALTERINDEXnameRENAMETOnew_name ...
Filter: (info~~'%bill%'::text)->IndexOnlyScan using t2_pkeyont2 (cost=0.15..12.14rows=266width=4) (actual time=0.009..0.025rows=266loops=1) Heap Fetches:0Planning Time:107.100ms Execution Time:0.502ms 3.1.运算类型: 执行计划运算类型操作说明是否有启动时间 ...
ORDER BY tablename, indexname; 6 系统中指定表建立的约束 SELECT constraint_name, constraint_type FROM information_schema.table_constraints WHERE table_name = '表名'; 7 对某个约束的详细信息的展示 SELECTc.conname ASconstraint_name, CASEc.contype ...