![]() In this example, we used an asterisk ( *) in the SELECT clause, which is a shorthand for all columns. The following query uses the SELECT statement to select data from all columns of the customer table: SELECT * FROM customer Code language: SQL (Structured Query Language) ( sql ) ![]() Suppose you just want to know the first name, last name and email of customers, you can specify these column names in the SELECT clause as shown in the following query: SELECTĬustomer Code language: SQL (Structured Query Language) ( sql ) 3) Using PostgreSQL SELECT statement to query data from all columns of a table example 2) Using PostgreSQL SELECT statement to query data from multiple columns example The semicolon is also used to separate two SQL statements. It is used to signal PostgreSQL the end of an SQL statement. The semicolon is not a part of the SQL statement. Notice that we added a semicolon ( ) at the end of the SELECT statement. This example uses the SELECT statement to find the first names of all customers from the customer table: SELECT first_name FROM customer Code language: SQL (Structured Query Language) ( sql ) 1) Using PostgreSQL SELECT statement to query data from one column example We will use the following customer table in the sample database for the demonstration. Let’s take a look at some examples of using PostgreSQL SELECT statement. By convention, we will use all the SQL keywords in uppercase to make the queries easier to read. It means that SELECT is equivalent to select or Select. Note that the SQL keywords are case-insensitive. PostgreSQL evaluates the FROM clause before the SELECT clause in the SELECT statement: ![]() If you do not query data from any table, you can omit the FROM clause in the SELECT statement. Second, specify the name of the table from which you want to query data after the FROM keyword. ![]() The select list may also contain expressions or literal values. If you want to select data from all the columns of the table, you can use an asterisk ( *) shorthand instead of specifying all the column names. If you specify a list of columns, you need to place a comma ( ,) between two columns to separate them. First, specify a select list that can be a column or a list of columns in a table from which you want to retrieve data.Let’s examine the SELECTstatement in more detail: Table_name Code language: SQL (Structured Query Language) ( sql ) The following illustrates the syntax of the SELECT statement: SELECT Let’s start with the basic form of the SELECT statement that retrieves data from a single table. In this tutorial, you are going to focus on the SELECTand FROMclauses. Perform set operations using UNION, INTERSECT, and EXCEPT.Join with other tables using joins such as INNER JOIN, LEFT JOIN, FULL OUTER JOIN, CROSS JOIN clauses.Group rows into groups using GROUP BY clause.Select a subset of rows from a table using LIMIT or FETCH clause.Select distinct rows using DISTINCT operator.The SELECTstatement has the following clauses: It has many clauses that you can use to form a flexible query.īecause of its complexity, we will break it down into many shorter and easy-to-understand tutorials so that you can learn about each clause faster. The SELECT statement is one of the most complex statements in PostgreSQL. One of the most common tasks, when you work with the database, is to query data from tables by using the SELECT statement. Note that if you don’t know how to execute a query against the PostgreSQL database using the psql command-line tool or pgAdmin GUI tool, you can check it out the connecting to PostgreSQL database tutorial. Summary: in this tutorial, you are going to learn how to use the basic PostgreSQL SELECT statement to query data from a table. ![]()
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