I often develop asp, but I am not very clear about the detailed statements. Here is a brief introduction.
Generally
Rs. open SQL, conn, are used to read data.
Modify data: rs. open SQL, conn, 1, 3
Delete data: You can directly delete data such as conn.exe cute ("delete * from new where id = 1.
Rs. Open Syntax: rs. Open Source, ActiveConnection, CursorType, LockType
Source is an
Label: conn =mysqljdbcutils.getconnection (); Statement PS=conn.createstatement (); Ps.addbatch ("Truncate Qb_showcount_asite_copy");
Ps.executebatch (); String Srcsql= "SELECT Convert" (Unhex (Hex (CONVERT (Community using latin1)) using UTF8) as Community, PID from Qb_menbercmmsets_list whe Re site=7 "; stmt=conn.preparestatement (Srcsql); RS=Stmt.executequery (); Above is the empty command that executes before the following SQL statement executes//
Today to query their own installed sqlserver2008 is R2 version, search the next, found that a lot of people query this problem, now recorded as follows, through the version of the command queryAlso understand the older brother SQL Server version of the good, a look is very clear, record
1. View SQL Server 2005/2008 version number
The code is as follows
Copy Code
Select SERVERPR
SQLServer how to use the T-SQL command to query a database in which tables, convenient table operations, need friends can refer to the next
SQLServer how to use the T-SQL command to query a database in which tables, convenient table operations, need friends can refer to the next
1. query all tables in SQL:
Select TABLE_NAME FROM database name. INFORMATION_SCHE
SQL Server database management common SQL and T-SQL statements
1. view the database version
Select @ version
2. view the operating system parameters of the machine where the database is located
Exec master .. xp_msver
3. view database startup parameters
Sp_configure
4. view the database startup time
Select convert (varchar (30), login_time, 120) from master .. sy
SQL connections (2) -- SQL Reading Notes, SQL Reading Notes
Chapter 1 in SQL Learning Guide
1.4 outer connections
In multi-table join, the connection condition may not match all rows in the table. For example, when the account table is connected to the customer table, the value of the cust_id column in the account tabl
SQL UNION operatorThe UNION operator is used to combine the result set of two or more SELECT statements.Note that the SELECT statement inside the UNION must have the same number of columns. The column must also have a similar data type. Also, the order of the columns in each SELECT statement must be the same.SQL UNION SyntaxSELECT column_name (s) from Table_name1unionselect column_name (s) from table_name2Note: By default, the UNION operator chooses a
process:
Square is a large object type. In this way, only an address is passed, rather than the entire object. Obviously, this process also improves the efficiency.
4. Summary
This article discusses the compilation principle, development process, and development skills of dynamic SQL. After introducing this article, I believe that readers have a general understanding of dynamic SQL program development
Beginner 1. Sql*plus is a product of a number of commands consisting of standard SQL and Oracle Companies
2. How to paste text on the Sql*plus operator interface: Select the text you want to paste, and then press the right key when you left.
3. Just in contact with Oracle, special attention must be paid to the commit order and rollback.
4. Learn about
Static SQL, dynamic SQL, and static SQL
Static
1. Common MemberCommon members belong to objects.Call with object
2. Static membersStatic members belong to the classCalled by Class Name
Class FenBi{Public int length; // common memberPublic string color ;//}
Static keywords
Static methods cannot contain common members.
The common method can contain static members.
1. query all tables in SQL:
Select TABLE_NAME FROM database name. INFORMATION_SCHEMA.TABLES Where TABLE_TYPE = 'base table' after execution, you can see the names of all tables created by yourself in the database.
2. query all tables and columns in SQL:
Select dbo. sysobjects. name as Table_name, dbo. syscolumns. name AS Column_name FROM dbo. syscolumns inner join dbo. sysobjects ON dbo. syscolumns. id
Complex SQL Split optimizationSplitting SQL is one of the most effective methods of performance optimization, which is to break down complex SQL into simple SQL by a certain logic, and finally execute an equivalent logic with the help of temporary tables, and have achieved efficient execution. I've been trying to write
SQL % found, SQL % notfound, SQL % rowcountWhen executing the DML (insert, update, delete) statement, you can use the following three implicit cursors (the cursor is an area in the memory that maintains the query results, which is opened when DML is run, when it is finished, use SQL % isopen to check whether it is enab
Tags: process variable assignment multiple meanings have a counter target based on nullI. T-SQL overviewThe programming language that SQL Server uses to manipulate the database is Transaction-sql, or T-SQL. T-SQL differs from PL/SQL
In fact, this is also a problem at work. To tell the truth, I am not willing to do it myself. I also want to write statements for queries, but I have not thoroughly studied this kind of information,Write SQL statements in JavaProgramAt the same time, I chose to be lazy.
First, if it is golden, of course there is no need to say that the Direct Write statement is similar to select. If it is PL/SQL, it is not
1. Query all tables in sql:
Select table_name from database name. Information_schema. Tables Where table_type= ' BASE table ' is executed, you can see the names of all the tables in the database that belong to you
2. Query all tables and columns in sql:Select Dbo.sysobjects.name as TABLE_NAME, dbo.syscolumns.name as column_name from Dbo.syscolumns INNER JOIN dbo.sysobject s on dbo.syscolumns.id = Dbo.sysobjects.id Where (dbo.sysobjects.xtype = '
SQL join is used to query data from these tables based on the relationship between the columns in two or more tables.Join and KeySometimes in order to get the complete result, we need to get the results from two or more tables. We need to execute the join.Tables in the database can be linked by keys. The primary key (Primary key) is a column, and the value of each row in the column is unique. In the table, the value of each primary key is unique. The
SQL Server parallel operation optimization prevents parallel operations from being restrained and affects SQL Execution efficiency and SQL Execution Efficiency
Why should I also say SQL Server Parallelism:
I have written many articles about SQL Server parallelism in the gard
1. query all tables in SQL:Select TABLE_NAME FROM database name. INFORMATION_SCHEMA.TABLES Where TABLE_TYPE = 'base table' after execution, you can see the names of all tables created by yourself in the database.2. query all tables and columns in SQL:Select dbo. sysobjects. name as Table_name, dbo. syscolumns. name AS Column_name FROM dbo. syscolumns inner join dbo. sysobjects ON dbo. syscolumns. id = dbo. sysobjects. id Where (dbo. sysobjects. xtype = 'U') AND (NOT (dbo. sysobjects. name LIKE '
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