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- How to create a database in SQL Server?
- SQL Server database creation method: first start the "SQL Server Management Studio" software; then log in to the software with a Windows account by default; then right-click the database and select [New Database]; finally enter the database name and save the database.
- SQL 5066 2020-06-23 13:47:16
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- How to use update statement to associate multiple tables?
- Methods for multi-table association in update statements: 1. Use the link of where clause, the code is [where exists (select1fromtmp_cust_city b]; 2. The modified value is calculated from another table, the code is [from tmp_cust_city b].
- SQL 13422 2020-06-29 17:13:10
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- What is SQL query and what are its characteristics?
- SQL query is to establish contact and communicate with various databases. Its characteristics are: 1. Real client/server architecture; 2. Graphical user interface, making system management and database management more intuitive and simple; 3. Rich Programming interface tools provide users with greater options for programming.
- SQL 10893 2020-06-22 16:56:06
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- What is the method to add data in batches using sql statements?
- Methods for adding data in batches using SQL statements include: 1. Use the statement [insert into table name (field) values (field value)] to execute them one by one; 2. Use the statement [insert into table name (field) values (field value 1), (field value 2), (field value)] to execute in batches.
- SQL 11430 2020-06-22 16:45:14
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- What are the SQL statements to delete table fields?
- The SQL statements to delete table fields are: 1. Delete columns without default values. The code is [alter table Test drop COLUMN BazaarType ]; 2. Delete columns with default values, the code is [alter table Test DROP COLUMN].
- SQL 6373 2020-06-22 15:35:19
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- What should I do if SQL Server 2008 installation is completed but fails?
- Solution to the problem that SQL Server 2008 installation is completed but failed: 1. Press the [win+r] shortcut key to open Run, enter regedit, and press Enter; 2. Find the MSSQLServer folder in the registry editor; 3. Right-click the folder , select the [Delete] option.
- SQL 15856 2020-06-30 13:07:20
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- SQL Server 2014 installation tutorial
- SQL Server 2014 installation tutorial: First install the ".Net Framework 3.5 sp1" software; then download the SQL Server installation package; then open the "setup.exe" file in the installation package and start the installation program; finally enter the product key to install. Can.
- SQL 5918 2020-06-19 15:16:00
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- What is the purpose of creating an index for a data table?
- The purpose of creating an index for a data table is: 1. To ensure the uniqueness of data through a unique index; 2. To speed up data retrieval; 3. To speed up the connection between tables; 4. To reduce grouping and sorting time; 5. To use Optimize hiders to improve system performance.
- SQL 18063 2020-06-19 13:18:12
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- Subqueries are generally divided into several types
- Subqueries are generally divided into three types: 1. where type subquery, which uses the inner query results as the comparison conditions of the outer query; 2. from type subquery, which uses the inner query results as a temporary table for the outer sql to be used again Query; 3. exists type subquery, get the results of the outer sql to the inner sql for testing.
- SQL 11866 2020-06-18 16:17:28
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- Detailed explanation of database update usage
- The database update statement is [UPDATE table name SET column name = new value WHERE column name = certain value]. Its function is to update the original data in the table. When used alone, use the where matching field.
- SQL 40883 2020-06-18 15:42:11
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- What is the meaning of GROUP BY in SQL query?
- In SQL queries, the meaning of GROUP BY is to group data according to specified rules. Its function is to group the query results according to the value of a certain column or multiple columns. Those with equal values are a group. The GROUP BY statement is generally used with the aggregate function. Use together.
- SQL 11979 2020-06-17 16:50:42
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- What is the statement to add fields in sql
- The standard SQL statement for adding fields to a data table is [alter table table name add(field field type) [default 'Enter default value'] [null/not null] ;].
- SQL 29008 2020-06-17 16:43:38
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- Redis persistence configuration (picture and text introduction)
- Redis is an open source, highly available non-relational database (NoSQL, not just a database) key-value database written in C language. Different from traditional databases, redis data is stored in memory, so the read and write performance is not generally high and can reach 100,000 operations per second.
- SQL 2940 2020-06-17 16:40:01
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- What is the sql command to delete a table?
- The SQL command to delete a table is [drop table (name of the table to be deleted)], where drop is to delete the entire table to release space, and delete is to delete the contents of the table.
- SQL 47027 2020-06-17 16:35:10
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- What is the command to create a data table in sql
- The command to create a data table in SQL is: [CREATE TABLE table_name (column_name column_type);]. Columns between data tables should be separated by commas in English. SQL statements in data tables are not case-sensitive.
- SQL 18782 2020-06-17 13:43:03
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