Page 68-SQL Programming Tutorials: Learn SQL Online-php.cn

Article Tags

SQL

Home

Technical articles

Database

SQL

What language is sql language?

SQL is a Structured Query Language (Structured Query Language), a special-purpose programming language, a database query and programming language, used to access data and query, update and manage relational database systems.

Aug 03, 2019 am 10:40 AM

sql

What is sql?

SQL (Structured Query Language) is a special-purpose programming language used for managing relational database management systems (RDBMS), or for stream processing in relational stream data management systems (RDSMS).

Aug 03, 2019 am 09:29 AM

sql

What is the core and most commonly used operation of the database?

The core and most commonly used operations of the database are insert, delete, update and select.

Jul 30, 2019 pm 02:57 PM

数据库

Select statement in sql language

The SELECT statement is used to select data from the database. The results are stored in a results table, called a result set. select syntax: SELECT column name FROM table name or SELECT*FROM table name.

Jul 26, 2019 am 11:43 AM

SQL，select

What is the sql command used to update records in the base table?

The sql command used to update records in the basic table is Update. Its standard format is: Update table name set field = value where condition. The usage method is slightly different depending on the source of the data.

Jul 24, 2019 pm 03:35 PM

SQL，更新记录

What problems may arise from concurrent database operations?

The quality of the concurrency control mechanism is one of the important indicators of measuring the performance of a database management system. Concurrent database operations may cause three problems: 1. Lost updates. 2. Non-repeatable reading. 3. Read "dirty data".

Jul 24, 2019 pm 03:17 PM

数据库

What is pointed out by using where clause in sql query

The where clause is used in sql queries to indicate the query conditions. The WHERE clause is used to extract records that meet specified criteria.

Jul 24, 2019 am 10:15 AM

SQL查询

Database backup and recovery solution

SQL SERVER backup method. Based on data security requirements, the recommended backup methods are a full backup once a week, a differential backup once a day, and a transaction log backup every half hour. Restoring a backup requires restoring the full backup first, then the differential backup, and then the transaction log backup. Restore the database to the state at the time of the transaction log backup

Jul 22, 2019 pm 06:22 PM

sql数据库

sql command to update records

There are two usages of SQL update statements: 1. Update a column: UPDATE table name SET column name = new value WHERE column name = a certain value. 2. Update several columns: UPDATE table name SET column 1 name = new value, column 2 name = new value WHERE column name = a certain value

Jul 22, 2019 pm 02:51 PM

sql

What is sql statement

SQL (Structured Query Language, Structured Query Language) statement is a language that operates on the database.

Jul 22, 2019 am 11:40 AM

sql

What is the command to insert records in sql

The sql command to insert records is INSERT INTO. In SQL, you can use the INSERT INTO command to add all fields and specific columns to the data table.

Jul 22, 2019 am 10:22 AM

SQL，命令

What does sql refer to?

SQL (Structured Query Language) is a database language with multiple functions such as data manipulation and data definition. This language has interactive characteristics and can provide users with great convenience. Database management systems should make full use of SQL language to improve computer application systems. work quality and efficiency.

Jul 20, 2019 pm 03:53 PM

sql数据库

MongoDB – Polymorphic schema built with schemas

Brief description: When all documents in a collection have a similar but not identical structure, we call it polymorphic pattern. Example: User posts need to be used in actual business. The general structure of the posts is the same, but the specific content needs to be displayed differently according to different post types.

Jul 01, 2019 pm 06:02 PM

MongoDB

MongoDB – Attribute schema built using schema

Go directly to understand attribute mode. It is particularly suitable for the following situations: there is a large document, but it actually has some similar fields, and a subset of these fields has the same characteristics. In the end, these subset fields actually need to be sorted or queried.

Jul 01, 2019 pm 04:37 PM

MongoDB