Basic SQL Queries

Writing an SQL query

The simplest SQL query can be written as "SELECT column_name FROM table_name". The "SELECT" statement in SQL is used for all queries. "column_name" refers to a particular column within a table, which is referred to as "table_name" in the "FROM" clause. There can be multiple column names in the query, which are are separated by commas.

A common way to perform quick queries on all the data in the table is to replace the column names with a "wildcard", which automatically refers to every column contained in the table. This is written as "SELECT * FROM table_name".

The most common optional clause used in basic SQL queries is the "WHERE" clause, which specifies a column and a value. This clause restricts the result set to only records in which the specified field matches the specified value. For example, one could write the query "SELECT * FROM customers WHERE name="Kelly" to return any records in the customers table with "Kelly" in the name field.

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