How do i select a single record in mysql?
Columns in SQL don't have a defined 'order'. Database systems generally keep track of an order for display purposes, but it doesn't make sense to ask a database to select a column by number. You need to know the column's name in order to query its contents. Show The same thing goes for the primary key (which, incidentally, may not be just a single column). You have to know which column it is, and what that column is named, in order to execute a query. If you don't know these things, or need to figure them out dynamically, then
will tell you the names of each column, and whether it is part of the primary key or not. It will return a table that you can read, like any other result. If you want to select a single row on the basis of primary key, use the WHERE clause. The syntax is as follows − SELECT * FROM yourTableName WHERE yourPrimaryKeyColumnName = someValue; To understand the above syntax, let us create a table. The query to create a table is as follows − mysql> create table selectWithPrimaryKey -> ( -> Id int NOT NULL AUTO_INCREMENT, -> Name varchar(20), -> Age int, -> Marks int, -> PRIMARY KEY(Id) -> ); Query OK, 0 rows affected (0.78 sec) Insert some records in the table using insert command. The query is as follows − mysql> insert into selectWithPrimaryKey(Name,Age,Marks) values('Larry',24,98); Query OK, 1 row affected (0.15 sec) mysql> insert into selectWithPrimaryKey(Name,Age,Marks) values('John',23,89); Query OK, 1 row affected (0.21 sec) mysql> insert into selectWithPrimaryKey(Name,Age,Marks) values('Mike',21,85); Query OK, 1 row affected (0.18 sec) mysql> insert into selectWithPrimaryKey(Name,Age,Marks) values('Sam',26,56); Query OK, 1 row affected (0.18 sec) mysql> insert into selectWithPrimaryKey(Name,Age,Marks) values('Carol',21,59); Query OK, 1 row affected (0.18 sec) mysql> insert into selectWithPrimaryKey(Name,Age,Marks) values('Bob',20,91); Query OK, 1 row affected (0.21 sec) mysql> insert into selectWithPrimaryKey(Name,Age,Marks) values('David',28,93); Query OK, 1 row affected (0.15 sec) Display all records from the table using select statement. The query is as follows − mysql> select *from selectWithPrimaryKey; The following is the output − +----+-------+------+-------+ | Id | Name | Age | Marks | +----+-------+------+-------+ | 1 | Larry | 24 | 98 | | 2 | John | 23 | 89 | | 3 | Mike | 21 | 85 | | 4 | Sam | 26 | 56 | | 5 | Carol | 21 | 59 | | 6 | Bob | 20 | 91 | | 7 | David | 28 | 93 | +----+-------+------+-------+ 7 rows in set (0.00 sec) The following is the query to select a single row from the table − mysql> select *from selectWithPrimaryKey where Id = 6; Here is the output − +----+------+------+-------+ | Id | Name | Age | Marks | +----+------+------+-------+ | 6 | Bob | 20 | 91 | +----+------+------+-------+ 1 row in set (0.00 sec)
Updated on 30-Jul-2019 22:30:24
To return only the first row that matches your The Here’s an example of a
The
Because the offset is optional, you can pass only one argument to the clause to simply limit the returned row count. For example, suppose you have a
To return only the first row, you need to execute the following SQL query:
The returned result set will be as shown below:
And that’s how you can Next, let’s see how you can add a custom order to change the order of the rows. MySQL select first row from a custom orderThe first row returned by the Usually, the rows in your table were ordered by the time they are inserted into the table. You can change the order of the rows returned by the The For example, the following SQL statement will sort the result using the
Add
the
And that’s how you can define a custom order and You may change the How do I select a specific record in MySQL?MySQL SELECT statement is used to retrieve rows from one or more tables. The statement can also include UNION statements and subqueries. SELECT statement is used to fetch rows or records from one or more tables.
How do I select a specific record in SQL?The SQL SELECT Statement. SELECT column1, column2, ... FROM table_name;. SELECT * FROM table_name;. Example. SELECT CustomerName, City FROM Customers;. Example. SELECT * FROM Customers;. How do I select a single row?In SQLJ, a single-row query can be executed and its result set data can be retrieved with a single statement: SELECT ... INTO . The INTO-clause contains a list of host variables or host expressions that receive the result set data.
How do I show only one record in SQL?The SQL SELECT TOP Clause. SQL Server / MS Access Syntax: SELECT TOP number|percent column_name(s) FROM table_name. ... . MySQL Syntax: SELECT column_name(s) FROM table_name. ... . Oracle 12 Syntax: SELECT column_name(s) FROM table_name. ... . Older Oracle Syntax: SELECT column_name(s) ... . Older Oracle Syntax (with ORDER BY): SELECT *. |