inrt values语句
Introduction
SQL is a programming language for managing data stored in relational databas. It provides veral commands that can be ud to perform different operations on the databas, and one of the commands is the INSERT INTO statement. The INSERT INTO statement is ud to add new records (rows) to an existing table in a databa. It can also be ud to populate a new table with data from another table. However, the data that is being inrted must conform to the data types and constraints of the columns in the target table.
The INSERT INTO statement
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元日的诗意The syntax for the INSERT INTO statement is as follows:
INSERT INTO {target table name} ({column name(s)}) VALUES ({value(s)});
The INSERT INTO statement is ud to add new records to an existing table in a databa. The "target table name" is the name of the table where the new records will be inrted. The "column name(s)" identifies the columns where the data will be inrted, and the "value(s)" are the actual data that will be inrted. The number of values inrted must match the number of columns specified.
Example:
Let's assume we have a table named "Customers" with the following columns: "CustomerID", "Name", and "Address". If we want to inrt a new record into this table, we would u the following command:最好用的输入法
INSERT INTO Customers (CustomerID, Name, Address) VALUES (1, 'John Doe', '123 Main St.');
This command would inrt a new record with a CustomerID of 1, Name of John Doe, and Address of 123 Main St. into the Customers table.
Inrting Data into Multiple Rows
The values to be inrted can also be specified for multiple rows in a single command. To do this, the VALUES keyword is ud to parate each row's data.
Example:
INSERT INTO Customers (CustomerID, Name, Address) VALUES (1, 'John Doe', '123 Main St.'), (2, 'Jane Smith', '456 Oak Rd.'), (3, 'Joe Johnson', '789 Elm St.');
This command would inrt three new records with customer IDs of 1, 2, and 3, each with their respective names and address.火车的历史
Using Subqueries
In addition to inrting data into a table from other tables, the INSERT INTO statement can be ud to inrt data that is retrieved by subqueries.
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lqr控制Example:
INSERT INTO Orders (OrderID, CustomerID, OrderDate) SELECT OrderID, CustomerID, OrderDate FROM PendingOrders WHERE OrderDate < DATEADD(Day, -7, GETDATE());
This command would lect all orders from the PendingOrders table that have an order date that is more than 7 days old and then inrt them into the Orders table.
Conclusion
The INSERT INTO statement is an important command in SQL. It is ud to inrt new records into a table, and it can also be ud to populate a new table with data from another table or subquery. While using the command, it is crucial to ensure that the values being inrted match the data types and constraints defined in the target table.
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