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
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
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 = '
1. SQL InjectionSo far, I have hardly seen anyone who has written a very complete article, or a very mature solution (there are certainly many people who can do it, and the problem is that it has not been spread. Unfortunately) I would like to give a few simple points to inspire everyone to think about and play a role in attracting others.
I. Principles of SQL Injection There are many ways to implement and
Tags: primary key first break range Ror add comment art DropSQL PRIMARY KEY ConstraintThe PRIMARY KEY constraint uniquely identifies each record in a database table. The primary key must contain a unique value. Primary key columns cannot contain NULL values. Each table should have a primary key, and each table can have only one primary key.SQL PRIMARY KEY Constraint on CREATE TABLEThe following SQL creates the PRIMARY KEY constraint in the "id_p" colu
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
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 '
Topic: Consumers from Madrid with fewer than 3 orders
Build table:
Copy Code code as follows:
SET NOCOUNT ON--When SET NOCOUNT is on, the count is not returned (representing the number of rows affected by Transact-SQL statements). Returns the count when SET NOCOUNT is off
Use SY
Go
If OBJECT_ID (' dbo. Orders ') is not null
DROP TABLE dbo. Orders
Go
If OBJECT_ID (' dbo. Customers ') is not null
DROP TABLE dbo. Customers
Go
CREATE
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
Label:The optimization of SQL statements is to convert poorly performing SQL statements into the same performance SQL statements with the same purpose.AI automatic SQL optimization uses AI technology to automatically rewrite SQL statements to find the best-performing equival
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
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
Abstract: In the PL/SQL development process, SQL, PL/SQL can be used to meet most of the requirements. However, in some special cases, standard SQL statements or DML statements in PL/SQL cannot meet your needs. For example, dynamic table creation or an uncertain operation mu
11. Microsoft SQL server network settingsOverview of Network ServicesSQL Server application interfaceNetwork Connection LibraryNetwork components and SQL server performanceNetwork MonitoringSummaryAfter you install Microsoft SQL Server, you must set its network settings. Up to now, you or your Microsoft Windows NT or Windows 2000 system administrator may have set
database parameterized ModeThere are two ways to parameterize a database, simple and mandatory (forced), and the default parameterization is "simple" by default.In simple mode, if the SQL is sent every time, unless it is exactly the same, it will be recompiled (special circumstances will be automatically parameterized, it is the focus of this article)The mandatory mode is to force the Adhoc SQL to be parame
After a DML statement is executed, the results of the DML statement are stored in four cursor attributes, which are used to controlProgramProcess or understand the program status. When running a DML statement, PL/SQL opens a built-in cursor and processes the result. The cursor is an area in the memory that maintains the query result. The cursor is opened when running the DML statement and closed after completion. Only
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