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You are not restricted by the column definitions in the database schema. You can join columns together so they're more human readable as one.
SQLite, PostgreSQL and Oracle
Use the concatenation operator ||.
SELECT <value or column> || <value or column> || <value or column> FROM <table>;
MS SQL
Use the concatenation operator +.
SELECT <value or column> + <value or column> + <value or column> FROM <table>;
MySQL, Postgres and MS SQL
Use the CONCAT() function.
SELECT CONCAT(<value or column>, <value or column>, <value or column>) FROM <table>;
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You're not restricted by the column
definitions in the database schema.
0:00
Remember in a previous course,
0:04
we used the AS keyword to alias the
column names to be more human readable.
0:06
Take this query for example.
0:12
We see that the first name, last name,
0:14
email, and
phone all have human readable aliases.
0:19
Let's run this query.
0:27
This generates a report with two columns,
the first name and the last name
0:30
that could be joined together to
save a little bit of visual clutter.
0:36
But how do we join these
two name columns together?
0:40
We can use an operator to join two
pieces of text from two columns,
0:44
called the concatenation operator.
0:49
Concatenate means to link or
join things together.
0:52
In this case, it's two strings of text.
0:56
The concatenation operator
in SQL Playgrounds
0:59
is two pipes of vertical line characters.
1:03
That's how you combine
two strings in SQLite.
1:06
You can type the pipe character on a US
keyboard by holding down the Shift and
1:10
backslash key.
1:15
In other SQL environments, you may need
to use a different set of characters for
1:17
the concatenation operator, or
sometimes it's even a function.
1:21
I'll include details in
the teacher's notes.
1:26
You can use the concatenation operator
to join two text values together
1:29
in the following way.
1:34
First, you specify the value or column,
1:36
the concatenation operator, and
then the second value or column.
1:40
In fact, you can join any number
of values or columns together.
1:45
You can even alias the newly joined
value to have an appropriate name.
1:50
Let's jump back to our customer example
and join the first name and last name.
1:55
Let's replace the first name alias and the
comma here with the concatenate operator.
2:01
Let's also change the alias
from last name to full name,
2:09
since that's what we're doing.
2:13
Let's run this.
2:15
As you can see, the first name and
last names are now joined.
2:17
But there's no space between
the first name and the last name.
2:22
That's because we didn't specify it.
2:26
SQL, like other programming languages,
require precise instructions.
2:29
Computers don't understand our intentions
without us explicitly telling them
2:33
what we want them to do.
2:37
We need to join another piece of text
in the middle, the value of the space.
2:39
Remember, we need to add quote marks
around the space character for
2:47
the database to recognize
it as a string of text.
2:51
When we run it now, it correctly shows
the full name with a space in the middle.
2:57
Performing concatenation doesn't
affect the data in the database,
3:03
it just presents it differently.
3:07
So you could still add
WHERE conditions and
3:09
orderings based on the last name, and
it should still work as you expect.
3:13
Now, you can join the values
from columns together and
3:27
insert strings of text between them too.
3:30
Remember to check the teacher's
notes to see the different ways
3:33
you can concatenate
strings in SQL databases.
3:36
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