在T-SQL 中提取部分字符串,可以使用内置的 `SUBSTRING` 函数。`SUBSTRING` 函数的语法如下: ``` SUBSTRING ( expression , start , l...
RIGHT ( character_expression , integer_expression ) --返回字符串中从右边开始指定个数的 integer_expression 字符。 SUBSTRING ( expression , start , length )--截取字符串 CHARINDEX ( expression1 , expression2 [ , start_location ] ) --返回字符串中指定表达式的起始位置,没有返回0 PATINDEX ( '%pat...
Notice how I've put a "-1" after the CHARINDEX function? This is because the CHARINDEX function is finding the space in the string, but we don't really want to include this in our resultset, so we're basically saying "find the position of the space minus one". A good...
SELECT SUBSTRING(@FullName, 1, CHARINDEX(' ',@FullName) - 1) AS FirstName, SUBSTRING(@FullName, CHARINDEX(' ',@FullName) + 1, LEN(@FullName)) AS LastName 结果为: 传递给SUBSTRING()函数的值是空格所在位置加上1,并将该值作为起始位置,这将是姓氏的第1个字母。由于不可能总是知道名字的长度...
其中,expressionToFind是要查找的字符或子字符串,expressionToSearch是要在其中查找的字符串,start_location是可选参数,表示开始查找的位置,默认为1。 对于计算字符串位置中的“1”,可以使用以下代码: 代码语言:sql 复制 DECLARE @string VARCHAR(100) = 'TSQL按位置计算字符串位置中的“1”' SELECT CHARIND...
IN、NOT IN 后面的子句返回的结果必须是一列,这一列的结果将会作为查询条件对应前面的条件。如 cid 对应子句的 id。 2.3 exists 和 not exists 子句查询示例 查询存在班级id为的学生信息: SELECT*FROMstudentWHEREEXISTS(SELECT*FROMclassesWHEREid=student.cidandid=3); ...
Cannot insert duplicate key row in object... Cannot insert the value NULL into column 'ID', table Cannot open backup device 'C:\TEMP\Demo.bak'. Operating system error 2(The system cannot find the file specified.). Cannot parse using OPENXML with namespace Cannot promote the transaction to...
The first argument is the string or the column name. The second argument is the index of the character at which the substring should begin. The third argument is the length of the substring. Watch out! Unlike in some other programming languages, in T-SQL the indexes start at 1, not 0....
To find any member of this string, we can use a simple algorithm that extracts a substring between two subsequent positions of delimiter:Member (1) = substring (string, 1, pos(1) – 1); Member (2) = substring (string, pos(1) + 1, pos(2) – pos(1) – 1); . . . Member (...
Access: MID(StringVal, StartPos, [length] )(length is optional) T-SQL: SUBSTRING(StringVal, StartPos, length )(length is required!) Finding a String within a String Access:SELECT INSTR(start, StringToSearch, StringToFind) T-SQL: SELECT CHARINDEX(start, StringToSearch, StringToFind) ...