sql where 2 conditions

We have to do not only write SQL, but also to write good performance of SQL statements.(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 a

Query records that meet the conditions in the table-WHERE clause bitsCN.com Query records that meet the conditions in the table-WHERE Clause When using SQL statements for query operations, developers or users are not interested in all the records

7. use the WHERE clause to query records that meet the conditions in the table bitsCN.com When using SQL statements for query operations, developers or users are not interested in all the records in the data table, but want to get the actual data

Query records that meet the conditions in a table-when the WHERE clause uses SQL statements for query operations, developers or users are not interested in all the records in the data table, however, if you want to obtain the data records you

When using SQL statements for query operations, developers or users are not interested in all the records in the data table, but want to get the actual data records, in this case, you need to restrict the query results. In SQL statements, you can

Conditions | Statements sometimes taking out all of the database records may just meet your requirements, but in most cases we usually only need to get a partial record. So how do you design the query? Of course it will be a bit more brain, and this

1. A question describes how an SQL statement is executed in a database? I believe many people will be interested in this issue. Of course, it is a huge problem to fully describe the lifecycle of an SQL statement in the database, it covers a series

*sql optimization based on ORACLE11GR2 reading notes * Third, cursor in OracleThe cursor in Oracle is a vector of SQL parsing and execution in an Oracle database and is a data structure for C (Oracle is written in C).There are two types of cursor in

Original address: http://www.cnblogs.com/dwfbenben/p/3307941.htmlWhen we use an expression as a column of output, we cannot use that column directly in the Where condition as a criterion. For example, the following SQL statement:select id (C1 + C2 )

In fleaphp, all functions used for database query require the query condition parameter $ conditions. The usage is as follows: Example: View plaincopy to clipboardprint?// $ Conditions Save the query Condition$ Conditions = 'level _ IX> 1 ′;// $