Unit: Intro to SQL: Querying and managing data
Mar 25, · Here's what that SQL query would look like: SELECT hair_color, COUNT(hair_color) FROM people_massachusetts AND birth_date BETWEEN '' AND '' GROUP BY hair_color; JOIN. There may be a time where you need to access information from two different tables in one SQL query. In SQL, you can use a JOIN clause to do this. Mar 27, · The SELECT statement can be described as the starting or the zero point of the SQL queries. The SELECT statement is used to retrieve data from the data tables. In the SELECT statement syntax, at first, we specify the column names and separate them with a comma if we use a single column we don’t use any comma in the SELECT statements.
Querying the table Opens a modal. Challenge: Box office hits database Opens a modal. Aggregating data Opens a modal. Opens a modal. Project: Design a store database Opens a modal. More advanced SQL queries. Challenge: Karaoke song selector Opens a modal. Querying How long to wait to donate blood after tattoo subqueries Opens a modal.
Challenge: Playlist maker Opens a modal. Challenge: The wordiest author Opens a modal. Who issues SQL queries? Challenge: Gradebook Opens a modal. Project: Data dig Opens a modal. Relational queries in SQL. Splitting data into related tables Opens a modal. JOINing related tables Opens a modal. Challenge: Bobby's Hobbies Opens a modal. Joining related tables with left outer joins Opens a modal.
Challenge: Customer's orders What is circuit court for a modal. Joining tables to themselves with self-joins Opens a modal.
Combining multiple joins Opens a modal. Challenge: FriendBook Opens a modal. Project: Famous people Opens a modal. More efficient SQL with query planning and optimization Opens a uss. Modifying databases with SQL. Using SQL to update a database Opens a modal. Challenge: Dynamic Documents Opens a modal. Altering tables after creation Opens a modal. Challenge: Clothing alterations Opens how to use in sql query modal.
Make your SQL safer Opens a modal. Project: App impersonator Opens a modal. Further learning in SQL. What to learn next Opens a modal. About this unit.
Dec 16, · Community Answer. If your field name is part_name for example, then your query goes like this if you want to select by the make: select part_name from [table_name] where make = [condition]. If you want to select with model year, it goes like this: select part_name from [table_name] where model_year = [condition]. SQL. Tutorial. SQL is a standard language for storing, manipulating and retrieving data in databases. Our SQL tutorial will teach you how to use SQL in: MySQL, SQL Server, MS Access, Oracle, Sybase, Informix, Postgres, and other database systems. 92 rows · IN Syntax. SELECT column_name (s) FROM table_name. WHERE column_name IN .
Essentially, SQL language allows us to retrieve and manipulate data on the data tables. In this article, we will understand and gain the ability to write fundamental SQL queries. At first, we will take a glance at the main notions that we need to know about in order to write database queries. SQL is the abbreviation of the Structured Query Language words and, it is used to query the databases. In this article, we will use the T-SQL standards in the examples.
Most simply, we can define the relational database as the logical structure in which data tables are kept that can relate to each other. A table is a database object that allows us to keep data through columns and rows. We can say that data tables are the main objects of the databases because they are holding the data in the relational databases. It is formed in the following columns.
We will use this table in our demonstrations in this article. The name of this data table is Student. In the second step, we write the FROM clause and as a last, we specify the table name.
Tip: We can easily try all these examples in this article by ourselves in the SQL Fiddle over this link. After navigating to the link, we need to clear the query panel and execute the sample queries. WHERE clause is used to filter the data according to specified conditions. The following example retrieves the students whose age is bigger and equal to Through the following query, we will retrieve the students whose names start with J character.
The following query returns data for the students whose marks are equal to and bigger than 40 and smaller and equal to The result set of the data can be sorted either ascending or descending. The DISTINCT clause is used to eliminate duplicate data from the specified columns so the result set is populated only with the distinct different values. Write a query that shows student names and ages in the descending order who takes Roman and Ancient History lessons.
In this article, we learned how we can write the basic SQL queries, besides that we demonstrated usage of the queries with straightforward examples.
FROM Student. SurName ,. Author Recent Posts. Esat Erkec. His current interests are in database administration and Business Intelligence. You can find him on LinkedIn. View all posts by Esat Erkec. Latest posts by Esat Erkec see all.