sql commands

Delete deletes a large table. It is not released between time and space. It is very slow because it occupies a large amount of system resources and supports rollback. The space is also occupied by this table.Truncate table Name (tablespace is

To know the size of each database, follow these steps: 1. Enter the information_schema database (which stores information about other databases) useinformation_schema; 2. query the size of all data: selectconcat (round (sum (data_length10241024), 2),

To know the size of each database, follow these steps: 1. Enter the information_schema database (which stores information about other databases) useinformation_schema; 2. query the size of all data: selectconcat (round (sum (data_length10241024), 2),

-- Create an object (table, view, stored procedure, function) command] Create Table/View/procedure/Function -- Create a table Create Table tabtestvb (Vbname varchar (10), value numeric (10 )) Go Create Table tabtestvb1 (Vbname varchar (10), value1

[Code = SQL] [/Code]-- Sentence skill-- Data OperationsSelect -- retrieve data rows and columns from database tablesInsert -- add new data rows to the database tableDelete -- delete data rows from a database tableUpdate -- update data in the

Delete deletes a large table. It is not released between time and space. It is very slow because it occupies a large amount of system resources and supports rollback. The space is also occupied by this table. Truncate table Name (tablespace is

Alter TABLE table1 ALTER COLUMN [name] varchar () NULL; Table1 Table Name Name field name why add [], because name is the SQL keyword will conflict error, so just in case. If the name field has already created an index, you must delete the index

Recently, I am working on a small project. I need to allow my colleagues to access the database under my computer, so I have to set up remote access to my database. It took a long time to complete the process, share your experience here. My

The use testdb//using command toggles the current database, and if the database does not exist, a new one is created first. Db.users.insert ({' name ': ' Xumingxiang ', ' sex ': ' Man '})//This command inserts a piece of data into the Users

Remote access Mysql-h localhost-uroot-p Modify password Mysqladmin-uroot-proot Password Admin If the original password is empty Mysqladmin-uroot Password Admin Display version number, status, process information, etc. Mysqladmin Version

You can quickly complete the form design by pasting the following code directly onto a blank form:Object Dbgrid1:tdbgrid left = 0 Top = 0 Width = 265 Height = 338 Align = Alleft DataSource = DataSource1 TabOrder = 0 Titlefont.charset =

db=# \helpAvailable Instructions:ABORTALTER AGGREGATEALTER COLLATIONALTER CONVERSIONALTER DATABASEALTER DEFAULT PrivilegesALTER DOMAINALTER EVENT TRIGGERALTER EXTENSIONALTER FOREIGN DATA WRAPPERALTER FOREIGN TABLEALTER FUNCTIONALTER GROUPALTER

PHP can use the least effort and the most fun to build a dynamic website. To create a dynamic website, we need to use a database to retrieve account information, spread dynamic news, and store Forum articles. In terms of using the most common MySQL

Code used to prevent SQL injection attacks. SQL injection attacks use designed vulnerabilities to run SQL commands on the target server and perform other attacks, when SQL commands are dynamically generated, the number of SQL injection attacks that

There are several default configuration templates after successful installation of MySQL, the list is as follows: my-hugecnf: For high-end product servers, including 1 to 2 GBRAM, mainly run mysqlmy-innodb-heavy-4Gini: for installation of innodb

This article mainly introduces the transaction features in MySQL, which is the basic knowledge in MySQL beginners. if you need it, you can refer to that the next transaction is a continuous set of database operations, it is like a single unit of

How can I use PHP to call a written c interface? for example, the database query statement in PHP is directly spelled out before the question, but it is inconvenient to maintain the database after modification, so I wrote a c interface. how can I

1.1.1 Summary A few days ago, the largest in ChinaProgramEmployeeCommunityThe user database of the csdn website was publicly released by hackers, And the login names and passwords of 6 million users were publicly leaked. Subsequently, user

I. Introduction to ADOADO (ActiveX Data Object) is a new interface for Microsoft database application development. It is a high-level database access technology built on top of ole db. Do not worry about this, even if you are, COM can also easily

SQL * Plus maintains system variables, also known as set variables. It can be used to create a special environment for SQL * Plus interaction, such as: SetSet the display width of the number data, the number of rows per page, and the column width.