因为数据类型成功插入后,查询出来值可能和你插入的值不一样,原因是长度截断和四舍五入。 精确类型不会发生截断且如果超长了直接报错,主要插入成功了,查出来的一定等于插入的结果。 看下具体例子: real:【不精确类型】【定长类型】PG10:六位有效数字,会四舍五入(PG14八位有效数字) 代码语言:javascript 代码运行次...
我们把int4和int8放在一个操作符族下,然后: ALTEROPERATORFAMILY integer_ops USING btree ADD -- 跨类型比较 int8 vs int4OPERATOR1< (int8, int4) ,OPERATOR2<= (int8, int4) ,OPERATOR3= (int8, int4) ,OPERATOR4>= (int8, int4) ,OPERATOR5> (int8, int4) ,FUNCTION1btint84cmp(int8,...
id | integer | name | character varying(20) | gender | boolean | join_date | date | dept | character(4) | Indexes: "idx_join_date_test" btree (join_date) "idx_test" btree (id) david=# select count(1) from test; count --- 1835008 (1 row) david=# 查看david 数据库大小 david...
AI代码解释 postgres=# create tabletpart_hash(a int primary key,b text)partition byhash(a)configuration(modulus5);CREATETABLEpostgres=# \d+tpart_hash Partitioned table"public.tpart_hash"Column|Type|Collation|Nullable|Default|Storage|Stats target|Description---+---+---+---+---+---+---+...
postgres=# create table t_hash (id int,infotext); CREATE TABLEpostgres=# insert into t_hash select generate_series(1,100), repeat(md5(random()::text),10000); INSERT 0 100 -- 使用b-tree索引会报错,因为长度超过了1/3的索引页大小postgres=# create index idx_t_hash_1 on t_hash using ...
pg_catalog | hashfloat4 |integer|real| normal pg_catalog | hashfloat8 |integer|doubleprecision| normal pg_catalog | hashinet |integer|inet| normal pg_catalog | hashint2 |integer|smallint| normal pg_catalog | hashint4 |integer|integer| normal ...
Fixed an issue in AVG aggregates which led to the termination of the connection for some integer datatypes. The index_id and indid column for respective views now returns the same value for indexes belonging to same object and the index_id is unique only within the object. Fixed an issue ...
createBigintTypeParser interval Produces interval in seconds (integer). createIntervalTypeParser numeric Produces a float. createNumericTypeParser timestamp Produces a unix timestamp (in milliseconds). createTimestampTypeParser timestamptz Produces a unix timestamp (in milliseconds). createTimestampWithTi...
Type modifier should be int32 not uint32 Sep 22, 2018 pgproto3 Add SCRAM authentication Apr 17, 2019 pgtype support binding of []int type to array integer Jan 15, 2019 stdlib [stdlib] Add support for creating a DB from pgx.Pool ...
这个问题问的好,刚开始我也是用的delete,但是不管sql怎么写,返回的都是一个Integer,然后转念一想,Mybatis是基于JDBC的,在JDBC中 增删改执行的都是 executeUpdate方法,这个方法返回整数就是受影响的行数,所以如果想在删除的同时,返回删除行的信息,就一定要用select。