about mysql

Ask a question about mysql traversing to json. I use PHP to pass a value to JqueryAJAX. $. parseJSON parsing I have learned how to query a record. if you want to upload multiple records. there is a problem. A record $ rowmysql_fetch_array ($ result);

Original: About MySQL Entity Framework 6 execute like query problem solutionI am not good at words, straight to the pointEnvironment: Ef6.0.0.0+mysql server5.6+mysqlconnector6.9.5.0The problem points are as follows:1 varUsername ="Admin";2

This article to you about the MySQL Chinese garbled problem how to solve (garbled problem perfect solution) of the relevant information, but also for you to collect some information about MySQL will appear in Chinese garbled reasons common points,

About MySQL related view display information: Database scope:First, view all databases: (just look at the number of databases and name)mysql> show databases;Second, to view the creation of a database information: (mainly see database options such as

When I first learned about MySQL, I saw the term undo log, but I didn't know what undo log was, so I had to figure out what undo log was before I could continue to see some MySQL data. What is the principle of undo log? How does it match the other

About MySQL innodb_autoinc_lock_mode, innodbstrictmode The innodb_autoinc_lock_mode parameter controls the behavior of locks when inserting data to a table in the auto_increment column; By setting it, you can achieve a balance between performance

About MySQL transaction isolation level and MySQL transaction isolation level This article elaborates four concepts related to databases: transactions, database read phenomena, isolation levels, and lock mechanisms. I. Transactions Let's take a look

Learn more about MySQL lock mechanism 1. MySQL concurrency and isolation control mechanism Meta-data metadata lock: implemented in the table cache and provides isolation for DDL (Data Definition Language. A special meta-data metadata type called

I would like to ask a question about MYSQL if the database contains a short string: AB BC CD So the word in my hand is a long string, such as ABCD. how should I write the SQL statement to match the character that contains the short word

Talk about MySql transactions and MySql transactions I have been working on Order projects recently and used transactions. MySql is used for our database, and innoDB is used for the storage engine. innoDB has good support for transactions. In this

Talking about mysql which can have nvl functions similar to oracle, oraclenvl Use ifnull instead of isnull Isnull is used to determine whether it is null. If the returned value is 1, it indicates null or 0, it indicates not null. Ifnull is

Optimization of database construction is probably mainly about index optimization, because it is impossible for us to modify the data structure, it seems that we can only use indexes to improve the database query efficiency. Below are some common

Comparison with MSSQL to learn about MYSQL (8) -- insert, update, delete, and mssqlmysql Similarly, it will only explain the difference between SQL Server and SQL Server. Insert Insert multi-row query results into the table Syntax INSERT INTO

About Mysql triggers and Mysql triggers First, the test version is Mysql 5.6. Then let's look at the trigger syntax. CREATE [DEFINER = {user| CURRENT_USER}] TRIGGERtrigger_name trigger_time trigger_eventONtbl_nameFOR EACH

Comparison with MSSQL to learn about MYSQL (5) -- Operator Security equals operator () This operator and = operator perform the same comparison operation, but can be used to determine the NULL value. When both operands are NULL, the return value

Ask a question about mysql and groupby grouping query. the data table field is of the datetime type, the saved value is 2009-02-10:20:11. I want to write an SQL statement for querying by number of days, that is, the number of records on the current

About Mysql EVENT bitsCN.com About the Mysql EVENT, Mysql EVENT has been tested for a long time by modifying the system EVENT. it is preliminarily estimated that it uses thread sleep and it is invalid to modify the system EVENT. It will not be

About MySQL database optimization we have briefly introduced some basic operations on MYSQL databases. This chapter describes the MYSQL database optimization problems for MYSQL database administrators. 1. optimize the MySQL server 1.1 MYSQL server

MySQL FAQs FAQs about MySQL Problem 1: the user cannot log on after the user is created on the local machine.Problem description:Create a database using root, and specify the user name that the database is allowed to access. Mysql> create

Notes about mysql: bitsCN.com 1. if the Key is null, the column value can be repeated, indicating that the column has no index or a non-leading column with a non-unique composite index.2. if the Key is PRI, this column is an integral part of the