这将创建一个名为change_column_type_in_table的迁移文件。 打开生成的迁移文件,并在up方法中使用Schema::table来更改列的数据类型。例如,要将名为column_name的列的数据类型从字符型更改为整型,可以执行以下操作: 打开生成的迁移文件,并在up方法中使用Schema::table来更改列的数据类型。例如,要将名为...
语法如下: --alter table table_name alter column {$column_name} set storage { PLAIN | MAIN | EXTERNAL | EXTENDED } ; postgres=# alter table test_toast alter column content2 set storage external; ALTER TABLE postgres=# \d+ test_toast Table "public.test_toast" Column | Type | Collation ...
在更改列类型之前,需要先备份数据库以防止意外数据丢失。 使用ALTER TABLE语句来更改列类型。例如,假设你要将名为"column_name"的列类型从ENUM更改为VARCHAR,可以使用以下语句: 使用ALTER TABLE语句来更改列类型。例如,假设你要将名为"column_name"的列类型从ENUM更改为VARCHAR,可以使用以下语句: ...
DO $$ BEGIN CREATE TYPE "public"."role" AS ENUM('admin', 'participant'); EXCEPTION WHEN duplicate_object THEN null; END $$; --> statement-breakpoint ALTER TABLE "user" ALTER COLUMN "role" SET DATA TYPE role;--> statement-breakpoint it causes error on Postgres as it lacks USING ...
ALTER COLUMN address TYPE varchar(80), ALTER COLUMN name TYPE varchar(100); ###To change an integer column containing Unix timestamps to timestamp with time zone via a USING clause: ALTER TABLE foo ALTER COLUMN foo_timestamp SET DATA TYPE timestamp with time zone ...
gender | character varying(1) | | |'M'::character varying# 修改列alter table gxl.test2 alter gendertypevarchar(10); alter table gxl.test2 drop column gender;# 删除表drop table gxl.test2; 3.表的约束 一种限制条件,比如说主键必须是唯一的,当出现重复的主键的时候会报错。
$table->integer('company_id')->change(); }); } 当我运行此迁移时,出现错误,表明该列无法自动转换为整数: In Connection.php line 664: SQLSTATE[42804]: Datatype mismatch: 7 ERROR: column "company_id" cannot be cast automatically to type integer HINT: You might need to specify "USING compa...
v_type TLOG.CHANGE_TYPE%TYPE; BEGIN SELECT sys_guid() INTO v_uid FROM DUAL; IF INSERTING THEN v_type := 'INSERT'; INSERT INTO TLOG VALUES (v_uid, 'PRODUCTS', v_type, :NEW.PRODUCT_ID, SYSTIMESTAMP); INSERT INTO TCOL VALUES (v_uid, 'PRODUCT_NAME', :NEW.PRODUCT_NAME, :NEW.PR...
{COLUMNREF :fields ("sc" "degree") :location 26 } :location 26 } ) :fromClause ( {RANGEVAR :schemaname <> :relname student :inh true :relpersistence p :alias {ALIAS :aliasname st :colnames <> } :location 41 } {JOINEXPR :jointype 0 :isNatural false :larg {RANGEVAR :schemaname...
def change add_column :movies, :like_user_ids, :integer, :array => true, :default => '{}' end # 使用PG内置扩展intarray:https://www.postgresql.org/docs/current/static/intarray.html #对intarray的求交集操作可以利用gin or gist索引 ...