PostgreSQL Flow account (fifth day): adding and deleting changes

Add: Insert

INSERT into Products (product_no, name, price) VALUES

(1, ' Cheese ', 9.99),

(2, ' Bread ', 1.99),

(3, ' Milk ', 2.99);

You can insert more than one row of data at a time.

INSERT into Products (product_no, name, Price) VALUES (1, ' Cheese ', DEFAULT);

INSERT into Products DEFAULT VALUES;

INSERT into Products (product_no, name) VALUES (1, ' Cheese ');

INSERT into Products VALUES (1, ' Cheese ');

Inserts a default value, assigns a value from left to right, no value or unspecified value, or explicitly assigns all columns a default value.

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Delete: Delete

DEDELETE FROM products;

LETE FROM products WHERE price = 10;

Delete the record that satisfies the Where condition or

Delete all records (if a Where condition is not provided)

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Change: Update

To update existing rows, use the? Update?command. This requires three pieces of information:

1. The name of the table and column to update
2. The new value of the column
3. which row (s) to update

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UPDATE mytable SET A = 5, B = 3, c = 1 WHERE a > 0;

UPDATE Products SET Price = Price * 1.10;

You can update all records, or you can update a record, depending on where condition.

You can update multiple fields.

If no record satisfies the Where condition, no error is recorded.

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Check: Select

PostgreSQL Flow account (fifth day): adding and deleting changes