sql string compare function

A string is usually used as an action object, such as finding a substring in a string, seeking a substring, inserting a substring at a point in a string, and deleting a substring. The necessary and sufficient condition for two strings to be equal is

String is a piece of cake, I summarize some common processing string functions. 1. Determine the length of a string This is one of the most obvious examples of the article, the question is how we can determine the length of a string, and here we

1. Current system date, timeSelect GETDATE ()2. DateAdd returns a new datetime value based on adding a period of time to the specified dateExample: Add 2 days to the dateSelect DATEADD (day,2, ' 2004-10-15 ')--return: 2004-10-1700:00:00.0003.

MS SQL Server Query optimization methodThere are many reasons for the slow speed of queries, which are common1, no indexes, or no indexes (this is the most common problem with query slowness, is the flaw in programming)2, I/o throughput is small,

Compare the time size of a string typeThe time in the database is varchar type, MySQL uses curdate () to get the current date, and SQL Server gets the current date by GETDATE ()1. Use strings directly to compareNote: To ensure that the two data

String functionsstring comparison functionsIf the length of the result is greater than the maximum value of the Max_allowed_packet system variable, the return value of the string value function is null. See section 7.5.2, "Tuning server parameters."

String function string comparison function if the result length is greater than the maximum value of the max_allowed_packet system variable, the return value of the string value function is NULL. See section 7.5.2 "Adjust server Parameters ". String

SQL statement optimization improves database performance and SQL statement database performance In systems with unsatisfactory performance, apart from the fact that the application load exceeds the server's actual processing capacity, it is more

Document directory 1. SQL injection vulnerability attack principles 2. SQL injection vulnerability detection methods and methods 3. SQL injection vulnerability Prevention Measures SQL Injection (sqlinjection) vulnerability attack is one of

Single-record functions in SQL 1. ASCIIReturns the decimal number corresponding to the specified character; SQL> select ASCII ('A') A, ASCII ('A') A, ASCII ('0') zero, ASCII ('') space from dual; A A zero space ------------------------------------ 65