sql case substring

isnull(aa,0)删除表数据：truncate table aaa 添加字段：ALTER TABLE table1 ADD col1 varchar(200) DEFAULT ‘2008-05-22‘修改字段名：alter table table1 rename column col1 to col2;修改字段属性：alter table table1 alter column col1 varchar(200) not null;修改默认值：alter table table1 add

Usage of Mysql string truncation function SUBSTRING description bitsCN.com feels that MySQL string function truncation characters are more powerful than program interception (such as PHP or JAVA), so here is a record, I hope it will be useful to you.

When creating the view today, it is very convenient to use string Truncation in MySQL. When creating the view today, it is very convenient to use string Truncation in MySQL. I feel that the string function of MySQL intercepts characters, which is

I feel that the string function of MySQL intercepts characters, which is more powerful than program interceptions (such as PHP or JAVA). So I want to make a record here and hope it will be useful to everyone.Function:1. Extract strings from the left

MS SQL Server Query optimization methodThere are many reasons for the slow speed of queries, which are common1, no indexes, or no indexes (this is the most common problem with query slowness, is the flaw in programming)2, I/o throughput is small,

Search for a lot of related information on the Internet and summarize the reasons for this situation mainly because of sorting rules:If no sorting rule is specifiedWhether the temporary table is case sensitive depends on the order of the tempdb

Start： -------------------------------------------------------------------------------- On the network, you see the methods of encrypting and decrypting SQL Server 2000 and SQL Server 2005 stored procedures, and then you analyze the code and find

Importing data from an Excel file to a SQL database is simple. Importing data from an Excel file to a SQL database is simple. -- Importing data from an Excel file to a SQL database is simple. Use the following statement: /* =========================

--From the Excel file, import the data into the SQL database, very simply, use the following statement directly: /*===================================================================*/ --If the table that accepts the data import already

The function of database backup and restore using T-SQL statementRepresents four points of knowledge in SQL Server:1. Get the default directory on a SQL Server server2. Use of Backup SQL statements3. Restores the use of SQL statements, taking into