Sql Case Insensitive

MySQL provides standard SQL pattern matching and a format based on pattern matching of extended regular expressions like Unix utilities such as vi, grep and sed. Standard SQL Pattern Matching SQL pattern matching allows you to match any single character with "_" and "%" with any number of characters (including zero characters). In MySQL, the default SQL mode is case-insensitive. Here are some examples. Note that you can not use = or! = While you are using SQL mode, and use LIKE or NOT LIKE to compare operators ...

In the development of friends especially and MySQL have contact friends will encounter sometimes MySQL query is very slow, of course, I refer to the large amount of data millions level, not dozens of, the following we take a look at the resolution of the query slow way. -Often find developers looking up statements that are not indexed or limit n, which can have a significant impact on the database, such as a large table of tens of millions of records to scan all, or do filesort, and the database and server IO impact. This is the case above the mirrored library. And ...

This article mainly introduces the MySQL slow query analysis method, some time ago, I have set a record in the MySQL database to query SQL statements slower than 1 second. Think of a few very set method, there are several parameters of the name of life and death memories can not afford, so re-sort it yourself as a note. For troubleshooting bottlenecks to find out the performance, the most easy to find and solve the problem is MySQL slow query and did not have to use the index query. OK, began to find out MySQL implementation is not "cool" SQL statement. ...

1, MySQL exists text and blob: (1), the same in the text or BLOB column storage or retrieval process, there is no case conversion, when not running in strict mode, if you assign a BLOB or text column exceeds the maximum length of the column type value, the value is intercepted to ensure that the appropriate. If the truncated character is not a space, a warning is generated. Using strict SQL mode produces an error, and the value is rejected rather than intercepted and given a warning. Blob and text columns cannot have default values. When a blob is saved or retrieved ...

Insert data into the database table The INSERT INTO statement is used to add a new record to the database table. Syntax INSERT INTO table_name VALUES (value1, value2, ....) You can also specify the column in which you want to insert data: INSERT INTO table_name (column1, column2, ...) VALUES (value1, value2, ....) Note: SQL statements on ...

Hive in the official document of the query language has a very detailed description, please refer to: http://wiki.apache.org/hadoop/Hive/LanguageManual, most of the content of this article is translated from this page, Some of the things that need to be noted during the use process are added. Create tablecreate [EXTERNAL] TABLE [IF not EXISTS] table_name [col_name data_t ...

To select the data that matches the specified criteria, add the WHERE clause to the SELECT statement. WHERE clause To select the data that match the specified criteria, add a WHERE clause to the SELECT statement. Syntax SELECT column FROM table WHERE column operator value The following operators can be used with the WHERE clause: Operator Description = Equal! = Not equal> Greater than <...

SELECT DATA FROM A DATABASE TABLE A SELECT statement is used to select data from a database. Syntax SELECT column_name (s) FROM table_name Note: SQL statements are not case-sensitive. SELECT and select equivalent. In order for PHP to execute the above statement, we must use the mysql_query () function. This function is used to send queries or commands to MySQL. Example The following example selected stored in "Pers ...

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PHP's ability to handle strings is powerful and varied, but sometimes you need to choose the simplest and most ideal solution. 　　This article lists 10 common examples of string processing in PHP and provides the best way to handle them. 1. Determine the length of a string this is one of the most obvious examples of the article, the question is how we determine the length of a string, here we can not but mention the strlen () function: $text = "Sunny Day" ...