Listing people with their phone numbers (if any)List of students with their classname in current yearEfficiently accessing the databaseDatabase design with information of employees, their jobs, salaries and projectsListing employees and their project tasksComparing client lists with Cross JoinsGathering distinct patient diagnosis recordsSelecting product variants that satisfy all option criteriaSpeed up SQL queryRunning SQL Queries On A Worksheet (With Set Of Random Numbers Between 1-20 Filling Column A) Handled As An ADO
How to format long polynomial?
A case of the sniffles
Is it unprofessional to ask if a job posting on GlassDoor is real?
Does detail obscure or enhance action?
If human space travel is limited by the G force vulnerability, is there a way to counter G forces?
How can I make my BBEG immortal short of making them a Lich or Vampire?
Important Resources for Dark Age Civilizations?
Why does Kotter return in Welcome Back Kotter?
"You are your self first supporter", a more proper way to say it
Perform and show arithmetic with LuaLaTeX
Theorems that impeded progress
How to determine what difficulty is right for the game?
Roll the carpet
Why can't we play rap on piano?
Can an x86 CPU running in real mode be considered to be basically an 8086 CPU?
Why is 150k or 200k jobs considered good when there's 300k+ births a month?
When a company launches a new product do they "come out" with a new product or do they "come up" with a new product?
What is the word for reserving something for yourself before others do?
What does "Puller Prush Person" mean?
Does an object always see its latest internal state irrespective of thread?
What typically incentivizes a professor to change jobs to a lower ranking university?
How do I deal with an unproductive colleague in a small company?
Revoked SSL certificate
What is a clear way to write a bar that has an extra beat?
Listing people with their phone numbers (if any)
List of students with their classname in current yearEfficiently accessing the databaseDatabase design with information of employees, their jobs, salaries and projectsListing employees and their project tasksComparing client lists with Cross JoinsGathering distinct patient diagnosis recordsSelecting product variants that satisfy all option criteriaSpeed up SQL queryRunning SQL Queries On A Worksheet (With Set Of Random Numbers Between 1-20 Filling Column A) Handled As An ADO
.everyoneloves__top-leaderboard:empty,.everyoneloves__mid-leaderboard:empty,.everyoneloves__bot-mid-leaderboard:empty margin-bottom:0;
$begingroup$
I have the following tables in my database:
people: phones:
+----+------+ +-----------+------------+-------------+
| id | name | | person_id | number | description |
+----+------+ +-----------+------------+-------------+
| 1 | Jade | | 1 | 1234567890 | home |
| 2 | Ben | | 1 | 987654321 | office |
+----+------+ +-----------+------------+-------------+
I use a query with INNER JOIN
to select the name and phone numbers for each person:
SELECT
id,
name,
group_concat(
concat(
number,
' (',
description,
')'
) ORDER BY description SEPARATOR ','
) AS phones
FROM people INNER JOIN phones
ON person_id = id
GROUP BY id;
Results from the above query:
+----+------+--------------------------------------+
| id | name | phones |
+----+------+--------------------------------------+
| 1 | Jade | 1234567890 (home),987654321 (office) |
+----+------+--------------------------------------+
But I want to use this query to go through all the people in my database and not just the ones with phone numbers, so I added the following row to the phones table:
INSERT INTO phones VALUES (0, 0, NULL);
And then modified the ON
statement of the query to:
ON person_id = id OR person_id = 0
That way every person gets selected even if he has no phone numbers registered in the database:
+----+------+--------------------------------------+
| id | name | phones |
+----+------+--------------------------------------+
| 1 | Jade | 1234567890 (home),987654321 (office) |
| 2 | Ben | NULL |
+----+------+--------------------------------------+
Is this a proper way to achieve this? I don't really like the idea of having to make sure that the 0, 0, NULL
row will always stay in the database in order to ensure the queries will work as intended. (since the company I develop this for might decide to clear the database)
This implementation requires calling an ensureNullRow()
function every time before using this query, is this a good solution or would you do it differently?
sql join
$endgroup$
add a comment |
$begingroup$
I have the following tables in my database:
people: phones:
+----+------+ +-----------+------------+-------------+
| id | name | | person_id | number | description |
+----+------+ +-----------+------------+-------------+
| 1 | Jade | | 1 | 1234567890 | home |
| 2 | Ben | | 1 | 987654321 | office |
+----+------+ +-----------+------------+-------------+
I use a query with INNER JOIN
to select the name and phone numbers for each person:
SELECT
id,
name,
group_concat(
concat(
number,
' (',
description,
')'
) ORDER BY description SEPARATOR ','
) AS phones
FROM people INNER JOIN phones
ON person_id = id
GROUP BY id;
Results from the above query:
+----+------+--------------------------------------+
| id | name | phones |
+----+------+--------------------------------------+
| 1 | Jade | 1234567890 (home),987654321 (office) |
+----+------+--------------------------------------+
But I want to use this query to go through all the people in my database and not just the ones with phone numbers, so I added the following row to the phones table:
INSERT INTO phones VALUES (0, 0, NULL);
And then modified the ON
statement of the query to:
ON person_id = id OR person_id = 0
That way every person gets selected even if he has no phone numbers registered in the database:
+----+------+--------------------------------------+
| id | name | phones |
+----+------+--------------------------------------+
| 1 | Jade | 1234567890 (home),987654321 (office) |
| 2 | Ben | NULL |
+----+------+--------------------------------------+
Is this a proper way to achieve this? I don't really like the idea of having to make sure that the 0, 0, NULL
row will always stay in the database in order to ensure the queries will work as intended. (since the company I develop this for might decide to clear the database)
This implementation requires calling an ensureNullRow()
function every time before using this query, is this a good solution or would you do it differently?
sql join
$endgroup$
add a comment |
$begingroup$
I have the following tables in my database:
people: phones:
+----+------+ +-----------+------------+-------------+
| id | name | | person_id | number | description |
+----+------+ +-----------+------------+-------------+
| 1 | Jade | | 1 | 1234567890 | home |
| 2 | Ben | | 1 | 987654321 | office |
+----+------+ +-----------+------------+-------------+
I use a query with INNER JOIN
to select the name and phone numbers for each person:
SELECT
id,
name,
group_concat(
concat(
number,
' (',
description,
')'
) ORDER BY description SEPARATOR ','
) AS phones
FROM people INNER JOIN phones
ON person_id = id
GROUP BY id;
Results from the above query:
+----+------+--------------------------------------+
| id | name | phones |
+----+------+--------------------------------------+
| 1 | Jade | 1234567890 (home),987654321 (office) |
+----+------+--------------------------------------+
But I want to use this query to go through all the people in my database and not just the ones with phone numbers, so I added the following row to the phones table:
INSERT INTO phones VALUES (0, 0, NULL);
And then modified the ON
statement of the query to:
ON person_id = id OR person_id = 0
That way every person gets selected even if he has no phone numbers registered in the database:
+----+------+--------------------------------------+
| id | name | phones |
+----+------+--------------------------------------+
| 1 | Jade | 1234567890 (home),987654321 (office) |
| 2 | Ben | NULL |
+----+------+--------------------------------------+
Is this a proper way to achieve this? I don't really like the idea of having to make sure that the 0, 0, NULL
row will always stay in the database in order to ensure the queries will work as intended. (since the company I develop this for might decide to clear the database)
This implementation requires calling an ensureNullRow()
function every time before using this query, is this a good solution or would you do it differently?
sql join
$endgroup$
I have the following tables in my database:
people: phones:
+----+------+ +-----------+------------+-------------+
| id | name | | person_id | number | description |
+----+------+ +-----------+------------+-------------+
| 1 | Jade | | 1 | 1234567890 | home |
| 2 | Ben | | 1 | 987654321 | office |
+----+------+ +-----------+------------+-------------+
I use a query with INNER JOIN
to select the name and phone numbers for each person:
SELECT
id,
name,
group_concat(
concat(
number,
' (',
description,
')'
) ORDER BY description SEPARATOR ','
) AS phones
FROM people INNER JOIN phones
ON person_id = id
GROUP BY id;
Results from the above query:
+----+------+--------------------------------------+
| id | name | phones |
+----+------+--------------------------------------+
| 1 | Jade | 1234567890 (home),987654321 (office) |
+----+------+--------------------------------------+
But I want to use this query to go through all the people in my database and not just the ones with phone numbers, so I added the following row to the phones table:
INSERT INTO phones VALUES (0, 0, NULL);
And then modified the ON
statement of the query to:
ON person_id = id OR person_id = 0
That way every person gets selected even if he has no phone numbers registered in the database:
+----+------+--------------------------------------+
| id | name | phones |
+----+------+--------------------------------------+
| 1 | Jade | 1234567890 (home),987654321 (office) |
| 2 | Ben | NULL |
+----+------+--------------------------------------+
Is this a proper way to achieve this? I don't really like the idea of having to make sure that the 0, 0, NULL
row will always stay in the database in order to ensure the queries will work as intended. (since the company I develop this for might decide to clear the database)
This implementation requires calling an ensureNullRow()
function every time before using this query, is this a good solution or would you do it differently?
sql join
sql join
edited 6 mins ago
200_success
131k17157422
131k17157422
asked 12 hours ago
potatopotato
29710
29710
add a comment |
add a comment |
1 Answer
1
active
oldest
votes
$begingroup$
What you are describing is known asLEFT OUTER JOIN
SELECT
id,
name,
group_concat(
concat(
number,
' (',
description,
')'
) ORDER BY description SEPARATOR ','
) AS phones
FROM people LEFT OUTER JOIN phones
ON person_id = id
GROUP BY id;
inner join
=> give me only rows with records in both tablesleft outer join
=> give me all rows of from the left table along with any matching rows in the right..
New contributor
$endgroup$
add a comment |
Your Answer
StackExchange.ifUsing("editor", function ()
return StackExchange.using("mathjaxEditing", function ()
StackExchange.MarkdownEditor.creationCallbacks.add(function (editor, postfix)
StackExchange.mathjaxEditing.prepareWmdForMathJax(editor, postfix, [["\$", "\$"]]);
);
);
, "mathjax-editing");
StackExchange.ifUsing("editor", function ()
StackExchange.using("externalEditor", function ()
StackExchange.using("snippets", function ()
StackExchange.snippets.init();
);
);
, "code-snippets");
StackExchange.ready(function()
var channelOptions =
tags: "".split(" "),
id: "196"
;
initTagRenderer("".split(" "), "".split(" "), channelOptions);
StackExchange.using("externalEditor", function()
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled)
StackExchange.using("snippets", function()
createEditor();
);
else
createEditor();
);
function createEditor()
StackExchange.prepareEditor(
heartbeatType: 'answer',
autoActivateHeartbeat: false,
convertImagesToLinks: false,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: null,
bindNavPrevention: true,
postfix: "",
imageUploader:
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
,
onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
);
);
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function ()
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fcodereview.stackexchange.com%2fquestions%2f216927%2flisting-people-with-their-phone-numbers-if-any%23new-answer', 'question_page');
);
Post as a guest
Required, but never shown
1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
$begingroup$
What you are describing is known asLEFT OUTER JOIN
SELECT
id,
name,
group_concat(
concat(
number,
' (',
description,
')'
) ORDER BY description SEPARATOR ','
) AS phones
FROM people LEFT OUTER JOIN phones
ON person_id = id
GROUP BY id;
inner join
=> give me only rows with records in both tablesleft outer join
=> give me all rows of from the left table along with any matching rows in the right..
New contributor
$endgroup$
add a comment |
$begingroup$
What you are describing is known asLEFT OUTER JOIN
SELECT
id,
name,
group_concat(
concat(
number,
' (',
description,
')'
) ORDER BY description SEPARATOR ','
) AS phones
FROM people LEFT OUTER JOIN phones
ON person_id = id
GROUP BY id;
inner join
=> give me only rows with records in both tablesleft outer join
=> give me all rows of from the left table along with any matching rows in the right..
New contributor
$endgroup$
add a comment |
$begingroup$
What you are describing is known asLEFT OUTER JOIN
SELECT
id,
name,
group_concat(
concat(
number,
' (',
description,
')'
) ORDER BY description SEPARATOR ','
) AS phones
FROM people LEFT OUTER JOIN phones
ON person_id = id
GROUP BY id;
inner join
=> give me only rows with records in both tablesleft outer join
=> give me all rows of from the left table along with any matching rows in the right..
New contributor
$endgroup$
What you are describing is known asLEFT OUTER JOIN
SELECT
id,
name,
group_concat(
concat(
number,
' (',
description,
')'
) ORDER BY description SEPARATOR ','
) AS phones
FROM people LEFT OUTER JOIN phones
ON person_id = id
GROUP BY id;
inner join
=> give me only rows with records in both tablesleft outer join
=> give me all rows of from the left table along with any matching rows in the right..
New contributor
New contributor
answered 11 hours ago
CharlesCharles
1363
1363
New contributor
New contributor
add a comment |
add a comment |
Thanks for contributing an answer to Code Review Stack Exchange!
- Please be sure to answer the question. Provide details and share your research!
But avoid …
- Asking for help, clarification, or responding to other answers.
- Making statements based on opinion; back them up with references or personal experience.
Use MathJax to format equations. MathJax reference.
To learn more, see our tips on writing great answers.
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function ()
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fcodereview.stackexchange.com%2fquestions%2f216927%2flisting-people-with-their-phone-numbers-if-any%23new-answer', 'question_page');
);
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown