string1、string2等的数量可以是零个或多个,分别表示需要合并的字符串。 使用示例: 假设现在有一个名为employees的表格,其中包含员工的名字(first_name和last_name),需要将它们合并为一个字段(full_name)。 SELECT CONCAT(first_name, ' ', last_name) AS full_name FROM employees; 1. 输出: +---+ | f...
SQLRETURN SQLGetInfo( SQLHDBC ConnectionHandle, SQLUSMALLINT InfoType, SQLPOINTER InfoValuePtr, SQLSMALLINT BufferLength, SQLSMALLINT * StringLengthPtr); 参数 ConnectionHandle [输入] 连接句柄。 InfoType [输入]信息类型。 InfoValuePtr [输出]指向要在其中返回信息的缓冲区的指针。 根据所请求的 InfoT...
name初始ThirdAndFourthCharacters mastermst tempdbtmp modelmde msdbmdb 若要显示字符串常量abcdef的第二、第三和第四个字符,请使用以下查询。 SQL SELECTSUBSTRING('abcdef',2,3)ASx; 结果集如下。 输出 x --- bcd B. 将 SUBSTRING 与文本、ntext 和图像数据配合使用 备注 若要运行...
instr(str, substr) - Returns the (1-based) index of the first occurrence ofsubstrinstr. Examples:> SELECT instr('SparkSQL', 'SQL');6 Examples:>SELECT locate('bar', 'foobarbar'); 4 14.space 在字符串前面加n个空格 space(n) - Returns a string consisting ofnspaces. ...
ASCII values for extended characters Assign empty string '' if datetime is null Assign EXEC output to Variable Assigning NULL value to column name using Case Statement of where is SQL SERVER 2008 atomic if not exists() and insert or update Attempt to fetch logical page (1:155534) in databas...
The second through fourth characters of the code are numbers that represent the letters in the expression. The letters A, E, I, O, U, H, W, and Y are ignored unless they're the first letter of the string. Zeroes are added at the end if necessary to produce a four-character code....
注:You can use the LENGTH function to find the number of characters in a string。 4、Show the name and the capital where the first letters of each match. Don't include countries where the name and the capital are the same word.
Suites can be built from other suites and tests, allowing areas of interest to be grouped together, and even a "super suite" can be created that executes all tests. 3.12.3Test Naming Test names are limited to 120 bytes, so test names can be up to 120 characters for a single-byte char...
nameis the constraint name, if specified, in the FOREIGN KEY clause. If a constraint name was not specified,nameis the first column name specified in the column list of the FOREIGN KEY clause followed by three periods. The same convention applies toconstraint-name1andconstraint-name2. ...
SQL also has the LEFT() function that does the opposite of the RIGHT()function. It returns gives the first left characters of the string. The syntax: LEFT(str, len) For example: SELECTLEFT('Microsoft',5) The result will be "Micro". 9. INSERT() You can use the INSERT() function to...