Sql Statements

The count query statement generated by entity Framework 4 was previously found to be a problem with the paging SQL statement that it generated today, and LINQ to SQL does not. 　　>>> take a look, and see! On code: Look at the generated SQL statement: 1. 　　Entity framework-generated SQL: A top, three from. 2. LINQ to SQL generated sql: ...

Today to introduce six more useful MySQL SQL statements, probably many people through PHP to achieve these functions. 　　1. Calculate the number of years you want to figure out how old this person is by birthdays. 　　SELECT Date_format (From_days to_days (now ())-To_days (@dateofbirth)), '%Y ' + 0; 2. Two time difference to obtain two datetime value difference. Suppose dt ...

SQL statement Import Excel to DB2 database Tutorial//method One SQL statement import Excel to DB2 database import from "C:booknow.csv" of del messages "D:msg.out" &n ...

A few suggestions to improve SQL execution efficiency: Try not to include subqueries in where; queries about time, try not to write: where To_char (dif_date, ' yyyy ') =to_char (' 2007-07-01 ', ' yyyy '); In the filter condition, the condition in which the maximum number of records can be filtered must be placed at the end of the WHERE clause, and the last table (underlying table, driving table) in the FROM clause will be first ...