sql commands

first, the MySQL database daily operation. 1. Start Mysql:/etc/init.d/mysql Start (the installation path in front of MySQL)2. Restart MySQL:/etc/init.d/mysql restart (the installation path in front of MySQL)3. Turn off MySQL:/etc/init.d/mysql stop

View system Current time HH24 24-hour MI is the right minuteSelect To_char (sysdate, ' Yyyy-mm-dd HH24:MI:SS ') from dualHH non-MM case-insensitive date mm system is considered a monthSelect To_char (sysdate, ' Yyyy-mm-dd HH:MM:SS ') from

To know the size of each database, proceed as follows:1. Access to the INFORMATION_SCHEMA database (information on other databases)Use INFORMATION_SCHEMA;2, query the size of all data:Select Concat (Round (sum (data_length/1024/1024), 2), ' MB ') as

Turn from:querying the underlying tables for all references in a view using SQL commandsUsing SQL commands to query all referenced base tables in a view before having written how to exploit all referenced tables in SQL query view this method does

Oracle command-line tools basic operations and SQL commands1. Basic Concepts1.1. Data typeBasic data Type (number,varchar2,date)O Racel supports the following internal data types:VARCHAR2 variable length string with a maximum of 2000

Create Student Case table: StudentCREATE TABLE Student (St_class char (8), St_no char (TEN) not null,st_name char (8) Not null,st_sex char (2), St_age Smallint,pri MARY KEY (St_no))Create a Course Setup table: SubjectCREATE TABLE subject (Su_no char

use of several SQL commands[Original 2006-4-21 14:22:05]size: big medium small 1.Update Batch ChangesFor example: A, b Two tables, B has the same field ID, will now cover the B_passerd in aA_passwordUpdate A A1Set A_password = (select

1. Rules for using SQL commands1, each order must be; End2. SQL command does not distinguish between letter case3. Use \c to terminate the execution of the current command2, the management of the library1, the basic operation of the library1. View

Tag: Row IDC width indicates wal linux localhost installation passwordInstalling MySQL on Buntu is simple and requires just a few commands to complete.1. sudo apt-get install Mysql-server2. Apt-get Isntall mysql-client3. sudo apt-get install

The value of the field A1 in table A is all assigned to the field B1 in Table B, which is associated with the ID of the two tables.Mode 1:UPDATE Hbsz071001.tac_bank ASETa.bankno=(SELECTBanknoFromHbsz0611.tac_bank bWHEREA.bankid =

Mysql>MySQL> UseInformation_schema;/*switch to INFORMATION_SCHEMA data*/ Databasechanged MySQL>MySQL> SelectConcatround(sum(Data_length/1024x768/1024x768),2),'MB') asData fromTables/*querying all data sizes*/ +----------+ |Data| +---------

Mysqldump-uroot-p--database X3GBK >x3gbk.sqlThe carriage return will depart, enter the password; Enter the password directly after-p, sometimes this format needs to be configured ~ ~ ~Online export on-line operation, export on-line;Drag to local,

1. Logging into the database/ Nologconn Heatmeter /heatmeter@orclConn sys/ as Sysdba2. View the database nameSelect from v$database;3. Database Import and Export exp water/ water @orcl file = c:\water.dmp owner= (water); Imp water / Water

View system Current time HH24 24-hour MI is the right minuteSelect To_char (sysdate, ' Yyyy-mm-dd HH24:MI:SS ') from dualHH non-MM case-insensitive date mm system is considered a monthSelect To_char (sysdate, ' Yyyy-mm-dd HH:MM:SS ') from

Establish dept and EMP Tables, and set the foreign keys of the EMP table with the dept_id in the Dept tableCREATE TABLE Dept (dept_name nvarchar () not NULL, dept_address nchar (+), dept_id int constraint pk_dept primary key--dept table's primary

1.net start/stop mysql start stop MySQLMysqladmin-uroot-p shutdown Stop MySQL2.show Create database/table XXX view Table/library Details3.show variables like '%character% ' view individual character sets4.show databases/tables View all

1. What is SQL injection attacks? The so-called SQL injection attack means that an attacker inserts an SQL command into the input field of a web form or the query string requested by the page, and deceives the server to execute malicious SQL

The so-called SQL injection attack means that an attacker inserts an SQL command into the input field of a web form or the query string requested by the page, and deceives the server to execute malicious SQL commands. In some forms, the content

The Java Database connection (JDBC) consists of a set of classes and interfaces written in the Java programming language. JDBC provides tools/database developers with a standard API that enables them to write database applications with a pure Java

Stored Procedures | Detailed articles on ASP and stored procedures (Stored procedures), but I doubt if the authors actually practiced them. I have consulted a lot of relevant data at the beginning of the class, and found that many of the methods