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Now in the last lesson we looked at how we would create new tables using the SQL language and how
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we would insert data into our tables. In this lesson
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we're going to look at the next part of CRUD which is 'R' for read. How would you read data in your table?
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Well the most often used keyword is the SQL SELECT keyword.
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And what this does is it allows you to read the data from your database.
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So for example whenever I right clicked on my tables and I clicked on show table you can see up here
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this syntax show up automatically because I'm able to show the table by running this statement. And what
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it says is SELECT * FROM products. Products is the table that I want to see and * stands for a
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wildcard.
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So it means select everything from the products table
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and this is why we see everything in our table.
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Now if you only wanted one column or two columns from this table then instead of asterix or * you
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can simply write SELECT name, price FROM this products table. And if you hit run you can see we've
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now removed that id column and we're reading from our database only the columns that we want.
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Now what if you only wanted a particular row from your database?
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Say for example you only wanted to see the first row,
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the one with an id of one.
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How would you do that with SQL? Well this is when you would need to search through your database by
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using the WHERE keyword.
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So this is the syntax we would SELECT a particular column or if you want to select all of the columns
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then you would put in asterisks and then we specify the table that you want to read the data from
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and then the WHERE is a search condition.
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So you could say something like
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WHERE country equals Mexico or WHERE custom ID equals one.
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If we tried out in the browser we can write SELECT everything which is * FROM the products table
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where id equals 1.
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So now if I hit run it isolates that single record where the id is equal to 1 and we select a single
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row.
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Now if you read the documentation you can see that there's other operators where you can get fancier
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than what we've done.
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So you can use things such as equal or greater or less than between like in all sorts of things
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to modify this WHERE statement so that you can select the pieces of data that you need.
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So this statement is for reading data from your database and grabbing the data that meet certain criteria.
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And you'll see the statement a lot
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when you start working with SQL databases.