sqlite

Database; use; embedded relational database

distinct

英[d??st??kt] US[d??st??kt ]

adj.Obvious, clear; outstanding, unusual; distinctive; exact

SQLite Distinct function syntax

Function:SQLite's DISTINCT keyword is used with the SELECT statement to eliminate all duplicate records and only obtain the unique record.

There may be a situation where there are multiple duplicate records in a table. The DISTINCT keyword is particularly meaningful when fetching such records, as it only fetches a unique record instead of duplicate records.

Syntax: The basic syntax of the DISTINCT keyword to eliminate duplicate records is as follows:

SELECT DISTINCT column1, column2,...columnN
FROM table_name
WHERE [condition]

SQLite Distinct function example

COMPANY 表有以下記錄：

ID          NAME        AGE         ADDRESS     SALARY
----------  ----------  ----------  ----------  ----------
1           Paul        32          California  20000.0
2           Allen       25          Texas       15000.0
3           Teddy       23          Norway      20000.0
4           Mark        25          Rich-Mond   65000.0
5           David       27          Texas       85000.0
6           Kim         22          South-Hall  45000.0
7           James       24          Houston     10000.0
8           Paul        24          Houston     20000.0
9           James       44          Norway      5000.0
10          James       45          Texas       5000.0
首先，讓我們來看看下面的 SELECT 查詢，它將返回重復(fù)的工資記錄：

sqlite> SELECT name FROM COMPANY;
這將產(chǎn)生以下結(jié)果：

NAME
----------
Paul
Allen
Teddy
Mark
David
Kim
James
Paul
James
James
現(xiàn)在，讓我們在上述的 SELECT 查詢中使用 DISTINCT 關(guān)鍵字：

sqlite> SELECT DISTINCT name FROM COMPANY;
這將產(chǎn)生以下結(jié)果，沒有任何重復(fù)的條目：

NAME
----------
Paul
Allen
Teddy
Mark
David
Kim
James