WHERE agent_code='A002': This line specifies a condition for filtering the results. It filters the results to only include rows where the value in the 'agent_code' column is 'A002'. This condition acts as a filter, allowing only rows with 'A002' as the agent code to be included in t...
A column often contains many duplicate values, and sometimes the information needed from a single column has to be distinct. Using the SELECT DISTINCT statement inSQL, we can filter out distinct values from a column. Syntax SELECT DISTINCT column1, column2, columnN FROM tablename; ...
一、SELECT 语句 SELECT<lines>[DISTINCT]<columns>[AS<alias>]INTO|APPEND[CORRESPONDINGFIELDSOF]<wa>TABLE<itab>[PACKAGE SIZE<n>]..FROM<dbtab>[AS <alias>]<options> UPTO<n>ROWS... [INNER]JOIN<dbtab> [AS <alias>]ON<cond><options>...WHERE<s> <opertor> <f>...GROUPBY<f1> <f2>.. ...
SQL Server : duplicate selectYour union query is doing the required duplication, what you need is...
#---会话2---mysql>>update table_logsetcode=9999999000where id=9999999;QueryOK,1rowaffected(0.02sec)Rows matched:1Changed:1Warnings:0---会话1---此时insert into select 返回结果 QueryOK,9096543rowsaffected(1min39.29sec)Records:9096543Duplicates:0Warnings:0mysql...
SQL select distinct on multiple columns is more useful in an RDBMS system to fetch unique records from various columns in a single table. We can use SQL to select distinct keywords on multiple columns from the specified table defined in the query. It will remove duplicate records from the col...
TheSELECT DISTINCTstatement is used when you want to return only unique (distinct) values in the result set. Whereas, a regularSELECTstatement without theDISTINCTkeyword retrieves all rows from the specified columns, including duplicate values. ...
开始我们拿sql到数据库查询平台查库执行计划,无奈这个平台有bug,delete语句无法查看,所以我们改成select,“应该”是一样。这个“应该”加了双引号,导致我们走了一点弯路。 EXPLAINSELECT*fromt_table_1wheretask_idin(selectidfromt_table_2whereuid=1)
Learn how to use SQL SELECT DISTINCT to remove duplicate rows from query results. Understand syntax and examples for returning unique data.
SQL Server select all rows except top row [duplicate]SQL 2012 also has the rather handy OFFSET ...