Working with data in SQL involves several operations such as inserting data, querying data, updating data, and deleting data. Here are some basic SQL commands for these operations:
1; Inserting Data
You can insert data into a table using the INSERT INTO statement. Here's an example:
INSERT INTO table_name (column1, column2, column3) VALUES (value1, value2, value3);
2; Querying Data
You can retrieve data from a table using the SELECT statement. Here's an example:
SELECT column1, column2 FROM table_name WHERE condition;
You can also retrieve all columns with *:
SELECT * FROM table_name;
3; Updating Data
You can update existing data in a table using the UPDATE statement. Here's an example:
UPDATE table_name
SET column1 = value1, column2 = value2
WHERE condition;
4; Deleting Data
You can delete data from a table using the DELETE statement. Here's an example:
DELETE FROM table_name WHERE condition;
Remember to replace table_name, column1, column2, value1, value2, and condition with your actual table name, column names, values, and condition.
Note: Be careful with the DELETE statement. If you omit the WHERE clause, it will remove all records from the table.
5; Joining Tables
You can join tables to combine rows from two or more tables based on a related column. Here's an example of an inner join:
SELECT column1, column2
FROM table1
INNER JOIN table2
ON table1.matching_column = table2.matching_column;
Remember, SQL is a powerful language for managing and manipulating data in relational databases. The commands above are just the basics. There are many more advanced commands and features available in SQL.
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