From aa9441a4e65b9256cc77e9b863e00d48679e6a21 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E8=B7=AF=E4=BA=BA?=
 <8737932+passers-bye@user.noreply.gitee.com>
Date: Thu, 2 Sep 2021 11:56:23 +0000
Subject: [PATCH] =?UTF-8?q?=E8=B5=B5=E5=90=91=E9=98=B3=E4=BD=9C=E4=B8=9A1?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 "\350\265\265\345\220\221\351\230\263.sql" | 64 ++++++++++++++++++++++
 1 file changed, 64 insertions(+)
 create mode 100644 "\350\265\265\345\220\221\351\230\263.sql"

diff --git "a/\350\265\265\345\220\221\351\230\263.sql" "b/\350\265\265\345\220\221\351\230\263.sql"
new file mode 100644
index 0000000..75175fb
--- /dev/null
+++ "b/\350\265\265\345\220\221\351\230\263.sql"
@@ -0,0 +1,64 @@
+use sllllllll;
+
+create TABLE Student
+(
+stuid int PRIMARY KEY,
+stuName VARCHAR(20) not null,
+stusj datetime not null,
+stucj datetime 
+);
+
+SELECT name,LENGTH(name) from user;
+select LENGTH('123ab韩国c'),OCTET_LENGTH('123ab美国c')
+
+select CHAR_LENGTH('123ab法国c')
+
+-- 替换
+select replace( '123425','2','asd')
+
+select INSERT('12342562789',2,3,'ABC')
+
+-- 截取
+SELECT select('123488',3)
+
+SELECT RIGHT('66666',3)
+
+select SUBSTRing('123456789',-5,3)
+
+-- 拼接
+select concat('wer','bbb','8888') 
+
+-- 逆序
+select REVERSE('123444')
+
+-- 大小写转换
+select UPPER('美国eeeEFG123')
+
+select LOWER('法国G123')
+
+-- 去空格
+select TRIM('       13  2      ');
+
+select LTRIM('       3   13     ');
+
+select RTRIM('       14   5        ');
+
+select REPLACE('    15  6      ',' ','');
+
+-- 时间函数
+select NOW()
+
+-- 流程控制
+-- IF 三目运算符
+select *,IF(stuid>=3,'小狗','小猫')改名 from Student;
+
+select *,
+(
+ CASE 
+WHEN stuid>=3 THEN
+		'小狗'
+ELSE
+		'小猫'
+END 
+)改名
+ from Student;
-- 
Gitee