Sql Case Statement Syntax

The complete collection of SQL statement operations deserves to be permanently stored the following statements are part of the MSSQL statement and are not available in Access. SQL classification: ddl-data Definition language (create,alter,drop,declare) dml-Data Manipulation Language (Select,delete,update,insert) dcl-Data Control Language (Grant,revoke, Commit,rollback first, briefly introduce the basic statement: 1, Description: Create number ...

Intermediary transaction http://www.aliyun.com/zixun/aggregation/6858.html ">seo diagnose Taobao guest Cloud host Technology Hall SQL injection attack is very harmful. Before explaining its methods of prevention, it is necessary for the database administrator to understand the rationale of the attack. 　　This is conducive to the administrator to take targeted preventive measures. 　　A simple example of SQL injection attacks. Statement: = "SE ...

For a lot of news at home and abroad, BBS and E-commerce sites are used asp+sql design, and write ASP programmers Many (there are a lot of just graduated), so, Asp+sql attack success rate is also relatively high. This kind of attack method has little to do with the NT version and the SQL version. There is no corresponding patch, because the loophole is caused by the programmer, and most of the book on ASP programming, the source code example has this flaw exists, in fact, just some legitimate ASP on the request of SQL, leaving endless trouble! A This attack method originated from ...

We want to do not only write SQL, but also to do a good performance of the SQL, the following for the author to learn, extract, and summarized part of the information to share with you! (1) Select the most efficient table name order (valid only in the Rule-based optimizer): The ORACLE parser processes the table names in the FROM clause in Right-to-left order, and the last table in the FROM clause (the underlying table driving tables) is processed first, In the case where multiple tables are included in the FROM clause, you must select the table with the least number of records as the underlying table. If...

SQL used to manipulate the database is generally divided into two kinds, one is the query, which is what we call the SELECT statement, the other is to update the statement, also known as data manipulation statements. The implication is to modify the data. There are 3 statements in the standard SQL, which are INSERT, UPDATE, and DELETE. There is another REPLACE statement in MySQL, so this article uses MySQL as a background to discuss how to make updates in SQL. First, INSERT and REPLACE I ...

This chapter explains the SELECT and select * Statements and the Select DISTINCT statements. This chapter explains the SELECT and select * Statements. The SQL SELECT statement SELECT statement is used to select data from a table. The result is stored in a result table (called a result set). SQL SELECT syntax Select column name from table name and: SELECT * FROM table name Comment: SQL statement for case ...

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 ...

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 <...

Update data in the database The UPDATE statement is used to modify data in a database table. Syntax UPDATE table_name SET column_name = new_value WHERE column_name = some_value Note: SQL is case insensitive. UPDATE and update equivalent. In order for PHP to execute the above statement, we must use mysql_query (function. This function is used to SQL ...

Delete data in the database DELETE FROM statement is used to delete records from the database table. Syntax DELETE FROM table_name WHERE column_name = some_value Note: SQL is case insensitive. DELETE FROM equivalent to delete from. In order for PHP to execute the above statement, we must use mysql_query (function. This function is used to send queries and SQL connections ...