SQL Cheat Sheet: Basics - SELECT, INSERT, UPDATE, DELETE, COUNT, DISTINCT, LIMIT

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SQL Cheat Sheet: Basics



CommandSyntaxDescriptionExample
SELECTSELECT column1, column2, ... FROM table_name; SELECT statement is used to fetch data from a database.SELECT city FROM placeofinterest;
WHERESELECT column1, column2, ...FROM table_name WHERE condition;WHERE clause is used to extract only those records that fulfill a specified condition.SELECT * FROM placeofinterest WHERE city == 'Rome' ;
COUNTSELECT COUNT * FROM table_name ; COUNT is a function that takes the name of a column as argument and counts the number of rows when the column is not NULL.SELECT COUNT(country) FROM placeofinterest WHERE country='Canada';
DISTINCTSELECT DISTINCT columnname FROM table_name;DISTINCT function is used to specify that the statement is a query which returns unique values in specified columns.SELECT DISTINCT country FROM placeofinterest WHERE type='historical';
LIMITSELECT * FROM table_name LIMIT number;LIMIT is a clause to specify the maximum number of rows the result set must have.SELECT * FROM placeofinterest WHERE airport="pearson" LIMIT 5;
INSERTINSERT INTO table_name (column1,column2,column3...) VALUES(value1,value2,value3...); INSERT is used to insert new rows in the table.INSERT INTO placeofinterest (name,type,city,country,airport) VALUES('Niagara Waterfalls','Nature','Toronto','Canada','Pearson');
UPDATEUPDATE table_name SET[[column1]=[VALUES]] WHERE [condition];UPDATE used to update the rows in the table.UPDATE placeofinterest SET name = 'Niagara Falls' WHERE name = "Niagara Waterfalls";
DELETEDELETE FROM table_name WHERE [condition]; DELETE statement is used to remove rows from the table which are specified in the WHERE condition.DELETE FROM placeofinterest WHERE city IN ('Rome','Vienna');

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