Database Administrator

SQLite is a lightweight associated database management system designed for embedded systems. SQLite is a database engine that implements self-dependency, pure client, zero configuration, and supports transactions. It was first developed by D.

. HelpView help information . Backup? DB? FILEBack up the database by using. backup [main |...] filename. The database name can be obtained through the. databases command. Generally, it is main, which can be omitted. filename is the disk file name. .

I. Common backup: The following method is a simple and commonly used SQLite database backup method, as shown in the following steps:1) Use the SQLite API or Shell tool to add a shared lock to the source database file.2). Use the Shell tool (cp or

1. Use EXPLAINThe EXPLAIN command can view the execution plan, which has been introduced in the previous blog. This method is our most important debugging tool.2. update statistics used in the execution plan in a timely manner Statistics are not

After the first run of iwms4.5, automatic SQL table creation is performed. The following describes how to convert access data to the SQL database. Note: Converting from access to SQL requires that the two versions have the same version number.

Paging stored procedures can be implemented in four ways: Row count, cursor, ascending-descending, and subqueryI remember someone tested the efficiency of these four methods from the best performance to the worst order-row count, cursor,

I. Database Design ProcessDatabase technology is the most effective means of information resource management. Database Design refers to constructing the optimal database mode for a given application environment, establishing a database and its

I used ACCESS to convert it to a SQL database. One of the columns containing text content has a data type of ntext with a length of 16 and is locked. It cannot be modified and can be left blank.When the character length is too LONG (thousands of

Designing an application system does not seem difficult, but it is not easy to optimize the system performance. In the development of tools, database design, shouldThere are multiple options for application structure, query design, and interface

Select *From openrowset ('Microsoft. Jet. OLEDB.4.0', 'Excel 8.0; HDR = YES; IMEX = 1; DATABASE = d: \ folder \ excel.xls ', Sheet1 $)------- NOTE ------Setting IMEX = 1 tells the driver to use Import mode. in this state, the registry setting

How the replication server works The operation of the SYBASE replication server product is as follows: Data Replication in StandBy mode Generally, the data on the replication node changes with the master node. Can I switch to the replication

Copy codeThe Code is as follows:Insert into table1 (id, name, address) VALUES (1, ygl, 'beijing') for T-SQL and PL/SQLSELECT id, name, address INTO table2 FROM table1 automatic creation of table2, T-SQL usageInsert into table2 (id, name, address)

PRIMARY KEY) Description from MSDN:A table usually has a column or a group of columns that uniquely identify the values of each row in the table. Such a column or multiple columns are called the primary key of the table, which is used to force the

1. Too much data. It cannot be put in a table. For example, monthly periodic table. 10 million a month, 0.12 billion in a year, so the accumulation will not work. Therefore, a table is based on periodic data. Even data in one cycle is divided into

Actually, ":" Calls the CAST function. Which fields can be converted into one another?You only need to study the cast function to obtain the answer to this question. The cast function information is managed in the pg_cast table of the system.The

Copy codeThe Code is as follows:If OBJECT_ID ('tb') is not null drop table tbIf OBJECT_ID ('temp ') is not null drop table TEMPIf OBJECT_ID ('fun _ nowprice') is not null drop FUNCTION FUN_NOWPRICEIf OBJECT_ID ('fun _ NOWQTY ') is not null drop

(1) MySQL:(1) JDBC driver jar package :( http://www.mysql.com) mm. mysql-2.0.2-bin.jar(2) Driver Class classpath: Driver = org. gjt. mm. mysql. Driver(3) database connection URL:Url = jdbc: mysql: // IP (hostName): 3306/DatabaseName.Url explanation:

Databases are also indispensable in the financial, leasing, retail, mailing, and medical fields. As the complexity of applications increases, databases with higher security requirements can meet the needs. To meet high-frequency application

Three-level database mode and two-level ing Shows the two-level ing of the database's three-level mode. Level 3 mode External mode: the logical structure of some data used by the application. One database can have multiple external Modes

When designing a relational database, you usually need to specify a primary key for each table. The primary key is the attribute or attribute group that uniquely identifies a row of records in the table. A table can only have one primary key,