(Instead of DISTINCT the key word ALL can be used to specify the default behavior of retaining all rows.) Obviously, two rows are considered distinct if they differ in at least one column value. Null values are considered equal in this comparison. 2、返回指定列唯一的任意行。 也可以使用...
select语法 数据 去重多个列 直接用distinct,后面的列都参与去重。只有code, name拼接的组合相同时,去掉重复的 去重指定列,保留其他列 当下遇到需求,需要将其中一个列去重,然后其他列随机取出就可以了。造成这种需求的原因是单表设计不合理,没有拆分成多表,造成多字
1) PostgreSQL SELECT DISTINCT one column example The following statement selects unique values from the bcolor column of the t1 table and sorts the result set in alphabetical order by using the ORDER BY clause. SELECT DISTINCT bcolor FROM colors ORDER BY bcolor; Output: bcolor --- blue gre...
[ ON join_condition | USING ( join_column [, ...] ) ] SELECT INTO 从一个查询的结果中定义一个新表。 SELECT [ ALL | DISTINCT [ ON ( expression [, ...] ) ] ] * | expression [ AS output_name ] [, ...] INTO [ TEMPORARY | TEMP ] [ TABLE ] new_table [ FROM from_item [...
SELECT [ ALL | DISTINCT [ ON ( expression [, ...] ) ] ] * | expression [ AS output_name ] [, ...] INTO [ TEMPORARY | TEMP ] [ TABLE ] new_table [ FROM from_item [, ...] ] [ WHERE condition ] [ GROUP BY expression [, ...] ] [ HAVING condition [, ...] ] [ ...
UNNEST( array_expression [, ... ] ) [WITH ORDINALITY][[AS] table_alias [(column_alias [, ... ])]] 如果没有指定table_alias,则使用函数名作为表名;在 ROWS FROM() 构造的情况下,使用第一个函数的名称。 如果未提供列别名,则对于返回基本数据类型的函数,列名也与函数名相同。对于返回复合类型的函...
postgres=# \helpSELECTCommand:SELECTDescription:retrieve rows from a table or viewSyntax:[WITH[RECURSIVE]with_query[,...]]SELECT[ALL|DISTINCT[ON(expression[,...])]][*|expression[[AS]output_name][,...]][FROMfrom_item[,...]][WHEREcondition][GROUPBYgrouping_element[,...]][HAVINGcondition...
PostgreSQL has a really interesting and powerful construct called SELECT DISTINCT ON. No, this is not a typical DISTINCT. This is different. It is perfect when you have groups of data that are similar and want to pull a singl
(list of SortBy) */Node*agg_filter;/* FILTER clause, if any */bool agg_star;/* argument was really '*' */bool agg_distinct;/* arguments were labeled DISTINCT */bool func_variadic;/* last argument was labeled VARIADIC */struct WindowDef*over;/* OVER clause, if any */int location...
navicat连接postgresql报错现象有小伙伴告诉我安装了新的postgresql使用navicat连接，报错column “datlastsysoid“ does not exist Line1:SELECT DISTINCT datalastsysoid FROM pg_database这主要是pgsql 15版本以后有些系统表的列名改了pg_database表里的这一个列被删除了导致的解决方法1：升级navicat将navicat升级到16...