ADD [ COLUMN ] column_type [ column_constraint [ ... ] ] DROP [ COLUMN ] column [ RESTRICT | CASCADE ] ALTER [ COLUMN ] column TYPE type [ USING expression ] ALTER [ COLUMN ] column SET DEFAULT expression ALTER [ COLUMN ] column DROP DEFAULT ALTER [ COLUMN ] column { SET | DROP...
ADD [ COLUMN ] column_type [ column_constraint [ ... ] ] DROP [ COLUMN ] column [ RESTRICT | CASCADE ] ALTER [ COLUMN ] column TYPE type [ USING expression ] ALTER [ COLUMN ] column SET DEFAULT expression ALTER [ COLUMN ] column DROP DEFAULT ALTER [ COLUMN ] column { SET | DROP...
建立user_code列,列类型和user_id保持一致 alter table t_test add column user_code int GENERATED ALWAYS AS(user_id) stored; 创建成功! 添加虚拟列 查看表中这个列是否有数据? select user_code,user_id,idfrom t_test; 查看表数据 首先可以查询这个列,可以看到列user_code和user_id的数据是一致的! 列...
AI代码解释 CREATETABLEtable_name(...){PARTITIONBY{RANGE|LIST}({column_name|(expression)} 创建主表时须指定分区方式,可选的分区方式为RANGE范围分区或LIST列表分区,并指定字段或表达式作为分区键。 创建分区的语法如下: 代码语言:javascript 代码运行次数:0 运行 AI代码解释 CREATETABLEtable_namePARTITIONOFparent...
ALTER TABLE [ ONLY ] name [ * ] action [, ... ] ALTER TABLE [ ONLY ] name [ * ] RENAME [ COLUMN ] column TO new_column ALTER TABLE name RENAME TO new_name其中action 可以是以选项之一:ADD [ COLUMN ] column_type [ column_constraint [ ... ] ] DROP [ COLUMN ] column [ ...
Create the file/etc/apt/sources.list.d/pgdg.listand add a line for the repository #Create the file repository configuration:sudo sh -c 'echo "deb http://apt.postgresql.org/pub/repos/apt $(lsb_release -cs)-pgdg main" > /etc/apt/sources.list.d/pgdg.list'#sudo sh -c'echo "deb ...
Column | Type | Modifiers ---+---+--- id | integer | name | character varying(20) | gender | boolean | join_date | date | dept | character(4) | Triggers: insert_tbl_partition_trigger BEFORE INSERT ON tbl_partition FOR EACH ROW EXECUTE PROCEDURE tbl_partition_insert_trigger() Numbe...
ALTER TABLE pgweb ADD COLUMN textsearchable_index_col tsvector GENERATED ALWAYS AS (to_tsvector('english', coalesce(title, '') || ' ' || coalesce(body, ''))) STORED; 然后创建一个GIN索引来加速搜索: CREATE INDEX textsearch_idx ON pgweb USING GIN(textsearchable_index_col); 准备好执行一个...
A new column backend_type identifies the process type. Prevent unnecessary checkpoints and WAL archiving on otherwise-idle systems (Michael Paquier) Increase the maximum configurable WAL segment size to one gigabyte (Beena Emerson) Add columns to pg_stat_replication to report replication delay ...
column?---1(1row)Asynchronous notification"ch1"received from server processwithPID1837.Asynchronous notification"ch1"received from server processwithPID1837.--session2postgres=# select1;?column?---1(1row)Asynchronous notification"ch1"received from server processwithPID1837.Asynchronous notification...