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- What are the three types of triggers?
- The types of triggers are: DML triggers, DDL triggers and login triggers. Trigger is a method provided by [SQL server] to programmers and data analysts to ensure data integrity; it is a special stored procedure related to table events; its execution is triggered by events.
- SQL 23217 2020-07-18 09:17:19
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- How to create a database in sql server?
- Visual creation can be done through the Sql Server Management Studio management tool. Method: 1. Log in to the management tool; 2. Right-click "Database" and select the "New Database" option; 3. In the pop-up window, enter the database name, set the database parameter values, and click "OK".
- SQL 6562 2020-07-17 11:08:54
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- What is the English abbreviation of database?
- The English abbreviation of database is: "DB" (Database). "DBMS" stands for Database Management System; a database is a collection of data that is stored together according to certain rules, can be shared with multiple users, has as little redundancy as possible, and is independent of applications.
- SQL 45158 2020-07-16 17:18:30
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- What are the stages of database design?
- According to the standardized design method, database design is divided into six stages: 1. Requirements analysis; 2. Conceptual structure design; 3. Logical structure design; 4. Database physical design; 5. Database implementation; 6. Database operation. and maintenance.
- SQL 36881 2020-07-16 13:38:51
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- What is the difference between left join, right join, inner join and full outer join?
- Difference: Left join returns all records in the left table and records with equal join fields in the right table; right join returns all records in the right table and records with equal join fields in the left table; inner join only returns records from both tables Join rows with equal fields; full outer join returns all records in the left and right tables and records with equal join fields in the left and right tables.
- SQL 64647 2020-07-16 11:31:49
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- Is sql the standard language for hierarchical databases?
- SQL language is not a standard language for hierarchical databases, but a standard language for relational databases. Structured Query Language SQL is a comprehensive, versatile, and highly functional relational database language; used for accessing data and querying, updating, and managing relational database systems.
- SQL 5102 2020-07-15 16:05:46
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- What is the function of drop keyword in sql statement
- The function of the drop keyword in the sql statement is to delete the table from the database. The drop statement will delete the table structure, as well as dependent constraints, triggers and indexes. After deletion, the stored procedures and functions that depend on the table will remain, but will become invalid.
- SQL 11762 2020-07-14 15:14:47
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- What is the command to update records in sql
- The sql command to update records is UPDATE. The UPDATE command is used to modify or update data in mysql. This command can update one or more fields at the same time, and can also specify any conditions in the WHERE clause.
- SQL 9504 2020-07-14 11:13:37
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- What are the data structures used in relational database systems
- The data structure used in relational database systems is a two-dimensional table. In a relational database system, all data is represented by a two-dimensional table structure, and these two-dimensional tables are usually called relationships. In a relational database, each relationship is a two-dimensional table.
- SQL 20912 2020-07-13 13:50:10
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- What are the basic techniques for database recovery?
- The basic techniques for database recovery are: 1. Data dump; 2. Register log files. Data dumping is the basic technique used in database recovery. Dumping is a process in which the DBA regularly copies the entire database to tape or another disk and saves it.
- SQL 13418 2020-07-13 09:19:58
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- What is the command to modify the table structure in sql statement?
- The command to modify the table structure in the sql statement is "ALTER TABLE", because in Visual FoxPro, there are two commands to modify the table structure, namely ALTER TABLE, which is used for SQL commands to modify the table structure; and MODIFY STRUCTURE, which is used in the table Modify the structure of the table in the designer.
- SQL 45605 2022-12-05 14:43:21
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- What are the rows in the data table called?
- Rows in a data table are called records; columns in a data table are called fields. A database is a "warehouse that organizes, stores and manages data according to a data structure"; it is a collection of large amounts of data that is stored in a computer for a long time, is organized, shareable and unified management.
- SQL 19075 2020-07-08 16:40:04
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- What objects does the database file contain at least
- The database file contains at least table objects. A database is a collection of large amounts of data that is stored in a computer for a long time, is organized, shareable, and uniformly managed. The database can be regarded as an electronic file cabinet. Users can add, query, update, delete and other operations on the data in the file.
- SQL 7275 2020-07-08 15:41:56
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- What is the relationship between DB, DBMS and DBS?
- The relationship between DB, DBMS and DBS is: DBS includes DB and DBMS. DBS refers to a database system. A database system generally consists of four parts: 1. Database; 2. Hardware; 3. Software; 4. Personnel.
- SQL 59576 2020-07-08 14:07:54
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- What is the logical structure of data in a relational database
- The logical structure of data in a relational database is a two-dimensional table. Relational database tables use two-dimensional tables to store data, which are logical groups of related information arranged in rows and columns. A database can contain any number of data tables.
- SQL 36337 2020-07-08 13:53:35