UNION SELECT after LEFT JOIN and JOIN

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    SELECT DISTINCT re.*

    FROM `reports` r

    LEFT JOIN `users` u

    ON u.`id_rep` = r.`id`

    JOIN `customers` c

    ON u.`id` = r.`uid`

    WHERE r.`uid` = '1' and r.`name` LIKE 'urgent'

    ORDER BY r.date DESC

Without making any modifications prior to the WHERE clause, would it be possible to use UNION (or a better approach) after the LIKE statement in order to SELECT from a fourth table called workers and ORDER the results BY r.date DESC?

edited Nov 27 at 20:34

asked Nov 25 at 22:44

user165684

I don't understand your EDIT. Please make a stab at the query; maybe it will be clearer then.
– Rick James
Nov 25 at 23:49

add a comment |

up vote
0
down vote

favorite

    SELECT DISTINCT re.*

    FROM `reports` r

    LEFT JOIN `users` u

    ON u.`id_rep` = r.`id`

    JOIN `customers` c

    ON u.`id` = r.`uid`

    WHERE r.`uid` = '1' and r.`name` LIKE 'urgent'

    ORDER BY r.date DESC

edited Nov 27 at 20:34

asked Nov 25 at 22:44

user165684

I don't understand your EDIT. Please make a stab at the query; maybe it will be clearer then.
– Rick James
Nov 25 at 23:49

add a comment |

up vote
0
down vote

favorite

    SELECT DISTINCT re.*

    FROM `reports` r

    LEFT JOIN `users` u

    ON u.`id_rep` = r.`id`

    JOIN `customers` c

    ON u.`id` = r.`uid`

    WHERE r.`uid` = '1' and r.`name` LIKE 'urgent'

    ORDER BY r.date DESC

edited Nov 27 at 20:34

asked Nov 25 at 22:44

user165684

    SELECT DISTINCT re.*

    FROM `reports` r

    LEFT JOIN `users` u

    ON u.`id_rep` = r.`id`

    JOIN `customers` c

    ON u.`id` = r.`uid`

    WHERE r.`uid` = '1' and r.`name` LIKE 'urgent'

    ORDER BY r.date DESC

mysql

edited Nov 27 at 20:34

asked Nov 25 at 22:44

user165684

edited Nov 27 at 20:34

asked Nov 25 at 22:44

user165684

edited Nov 27 at 20:34

asked Nov 25 at 22:44

user165684

asked Nov 25 at 22:44

user165684

asked Nov 25 at 22:44

user165684

I don't understand your EDIT. Please make a stab at the query; maybe it will be clearer then.
– Rick James
Nov 25 at 23:49

add a comment |

I don't understand your EDIT. Please make a stab at the query; maybe it will be clearer then.
– Rick James
Nov 25 at 23:49

I don't understand your EDIT. Please make a stab at the query; maybe it will be clearer then.
– Rick James
Nov 25 at 23:49

add a comment |

2 Answers
2

active

oldest

votes

up vote
1
down vote

Using Union and ORDER BY:

Be explicit with results form first query:

(SELECT DISTINCT rep.name, rep.date as rdate

FROM `reports_new` rep

LEFT JOIN `repuser_new` ru

ON ru.`id_rep` = rep.`id`

JOIN `clients` c

ON c.`id` = rep.`id_client`

WHERE ru.`id_user` = '1' and rep.`name` LIKE 'urgent')



UNION

(SELECT username,rdate FROM users)





ORDER BY rdate DESC

I assumed the second table had a date column. Otherwise and explicit value could be used.

edited Nov 25 at 23:47

answered Nov 25 at 22:59

danblack

1,4411212

There's an example of that in the manual page
– danblack
Nov 25 at 23:24

1

Try a new question. You're adding an amount of complexity beyond the initial question and without a full example with sample output clarification by comment is getting increasingly likely to be wrong.
– danblack
Nov 25 at 23:30

add a comment |

up vote
1
down vote

If I understand the question correctly, yes. Each of the following is OK, though not necessarily efficient:

SELECT ...

   FROM ( ( SELECT ... ) UNION ( SELECT ... ) ) AS x



SELECT ...

   FROM a

   JOIN ( ( SELECT ... ) UNION ( SELECT ... ) ) AS x ON ...



SELECT ...

   FROM a

   LEFT JOIN ( ( SELECT ... ) UNION ( SELECT ... ) ) AS x ON ...



SELECT ...

   FROM ( ( SELECT ... ) UNION ( SELECT ... ) ) AS a

   JOIN ( ( SELECT ... ) UNION ( SELECT ... ) ) AS x ON ...

etc. (I may have added more parentheses than necessary.)

More UNION tips:

Yes, the number of columns needs to be the same.

The default column names come from the first SELECT.

If you have a constant string in a column of the first SELECT, that limits the length of the matching string of the other SELECTs. (Simply pad with blanks to 'fix' the problem.)

If appropriate, use UNION ALL do avoid the de-duping phase, thereby being faster than UNION, which is the same as UNION DISTINCT.

edited Nov 26 at 0:13

answered Nov 25 at 23:47

Rick James

39.9k22257

@Rick the last 2 queries are equivalent. The ORDER BY is applied to the whole result set in both of them: dbfiddle.uk/…
– ypercubeᵀᴹ
Nov 25 at 23:58

1

@ypercubeᵀᴹ - Geez, I'm only a decade out of step -- bugs.mysql.com/bug.php?id=27848 "fixed" that in 2008 (5.0.56, 5.1.23). Thanks for rattling my cage.
– Rick James
Nov 26 at 0:12

add a comment |

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2 Answers
2

active

oldest

votes

2 Answers
2

active

oldest

votes

up vote
1
down vote

Using Union and ORDER BY:

Be explicit with results form first query:

(SELECT DISTINCT rep.name, rep.date as rdate

FROM `reports_new` rep

LEFT JOIN `repuser_new` ru

ON ru.`id_rep` = rep.`id`

JOIN `clients` c

ON c.`id` = rep.`id_client`

WHERE ru.`id_user` = '1' and rep.`name` LIKE 'urgent')



UNION

(SELECT username,rdate FROM users)





ORDER BY rdate DESC

I assumed the second table had a date column. Otherwise and explicit value could be used.

edited Nov 25 at 23:47

answered Nov 25 at 22:59

danblack

1,4411212

There's an example of that in the manual page
– danblack
Nov 25 at 23:24

1

Try a new question. You're adding an amount of complexity beyond the initial question and without a full example with sample output clarification by comment is getting increasingly likely to be wrong.
– danblack
Nov 25 at 23:30

add a comment |

up vote
1
down vote

Using Union and ORDER BY:

Be explicit with results form first query:

(SELECT DISTINCT rep.name, rep.date as rdate

FROM `reports_new` rep

LEFT JOIN `repuser_new` ru

ON ru.`id_rep` = rep.`id`

JOIN `clients` c

ON c.`id` = rep.`id_client`

WHERE ru.`id_user` = '1' and rep.`name` LIKE 'urgent')



UNION

(SELECT username,rdate FROM users)





ORDER BY rdate DESC

I assumed the second table had a date column. Otherwise and explicit value could be used.

edited Nov 25 at 23:47

answered Nov 25 at 22:59

danblack

1,4411212

There's an example of that in the manual page
– danblack
Nov 25 at 23:24

1

Try a new question. You're adding an amount of complexity beyond the initial question and without a full example with sample output clarification by comment is getting increasingly likely to be wrong.
– danblack
Nov 25 at 23:30

add a comment |

up vote
1
down vote

Using Union and ORDER BY:

Be explicit with results form first query:

(SELECT DISTINCT rep.name, rep.date as rdate

FROM `reports_new` rep

LEFT JOIN `repuser_new` ru

ON ru.`id_rep` = rep.`id`

JOIN `clients` c

ON c.`id` = rep.`id_client`

WHERE ru.`id_user` = '1' and rep.`name` LIKE 'urgent')



UNION

(SELECT username,rdate FROM users)





ORDER BY rdate DESC

I assumed the second table had a date column. Otherwise and explicit value could be used.

edited Nov 25 at 23:47

answered Nov 25 at 22:59

danblack

1,4411212

Using Union and ORDER BY:

Be explicit with results form first query:

(SELECT DISTINCT rep.name, rep.date as rdate

FROM `reports_new` rep

LEFT JOIN `repuser_new` ru

ON ru.`id_rep` = rep.`id`

JOIN `clients` c

ON c.`id` = rep.`id_client`

WHERE ru.`id_user` = '1' and rep.`name` LIKE 'urgent')



UNION

(SELECT username,rdate FROM users)





ORDER BY rdate DESC

I assumed the second table had a date column. Otherwise and explicit value could be used.

edited Nov 25 at 23:47

answered Nov 25 at 22:59

danblack

1,4411212

edited Nov 25 at 23:47

answered Nov 25 at 22:59

danblack

1,4411212

answered Nov 25 at 22:59

danblack

1,4411212

answered Nov 25 at 22:59

danblack

1,4411212

There's an example of that in the manual page
– danblack
Nov 25 at 23:24

1

Try a new question. You're adding an amount of complexity beyond the initial question and without a full example with sample output clarification by comment is getting increasingly likely to be wrong.
– danblack
Nov 25 at 23:30

add a comment |

There's an example of that in the manual page
– danblack
Nov 25 at 23:24

1

Try a new question. You're adding an amount of complexity beyond the initial question and without a full example with sample output clarification by comment is getting increasingly likely to be wrong.
– danblack
Nov 25 at 23:30

There's an example of that in the manual page
– danblack
Nov 25 at 23:24

Try a new question. You're adding an amount of complexity beyond the initial question and without a full example with sample output clarification by comment is getting increasingly likely to be wrong.
– danblack
Nov 25 at 23:30

add a comment |

up vote
1
down vote

If I understand the question correctly, yes. Each of the following is OK, though not necessarily efficient:

SELECT ...

   FROM ( ( SELECT ... ) UNION ( SELECT ... ) ) AS x



SELECT ...

   FROM a

   JOIN ( ( SELECT ... ) UNION ( SELECT ... ) ) AS x ON ...



SELECT ...

   FROM a

   LEFT JOIN ( ( SELECT ... ) UNION ( SELECT ... ) ) AS x ON ...



SELECT ...

   FROM ( ( SELECT ... ) UNION ( SELECT ... ) ) AS a

   JOIN ( ( SELECT ... ) UNION ( SELECT ... ) ) AS x ON ...

etc. (I may have added more parentheses than necessary.)

More UNION tips:

Yes, the number of columns needs to be the same.

The default column names come from the first SELECT.

If you have a constant string in a column of the first SELECT, that limits the length of the matching string of the other SELECTs. (Simply pad with blanks to 'fix' the problem.)

If appropriate, use UNION ALL do avoid the de-duping phase, thereby being faster than UNION, which is the same as UNION DISTINCT.

edited Nov 26 at 0:13

answered Nov 25 at 23:47

Rick James

39.9k22257

@Rick the last 2 queries are equivalent. The ORDER BY is applied to the whole result set in both of them: dbfiddle.uk/…
– ypercubeᵀᴹ
Nov 25 at 23:58

1

@ypercubeᵀᴹ - Geez, I'm only a decade out of step -- bugs.mysql.com/bug.php?id=27848 "fixed" that in 2008 (5.0.56, 5.1.23). Thanks for rattling my cage.
– Rick James
Nov 26 at 0:12

add a comment |

up vote
1
down vote

If I understand the question correctly, yes. Each of the following is OK, though not necessarily efficient:

SELECT ...

   FROM ( ( SELECT ... ) UNION ( SELECT ... ) ) AS x



SELECT ...

   FROM a

   JOIN ( ( SELECT ... ) UNION ( SELECT ... ) ) AS x ON ...



SELECT ...

   FROM a

   LEFT JOIN ( ( SELECT ... ) UNION ( SELECT ... ) ) AS x ON ...



SELECT ...

   FROM ( ( SELECT ... ) UNION ( SELECT ... ) ) AS a

   JOIN ( ( SELECT ... ) UNION ( SELECT ... ) ) AS x ON ...

etc. (I may have added more parentheses than necessary.)

More UNION tips:

Yes, the number of columns needs to be the same.

The default column names come from the first SELECT.

If you have a constant string in a column of the first SELECT, that limits the length of the matching string of the other SELECTs. (Simply pad with blanks to 'fix' the problem.)

If appropriate, use UNION ALL do avoid the de-duping phase, thereby being faster than UNION, which is the same as UNION DISTINCT.

edited Nov 26 at 0:13

answered Nov 25 at 23:47

Rick James

39.9k22257

@Rick the last 2 queries are equivalent. The ORDER BY is applied to the whole result set in both of them: dbfiddle.uk/…
– ypercubeᵀᴹ
Nov 25 at 23:58

1

@ypercubeᵀᴹ - Geez, I'm only a decade out of step -- bugs.mysql.com/bug.php?id=27848 "fixed" that in 2008 (5.0.56, 5.1.23). Thanks for rattling my cage.
– Rick James
Nov 26 at 0:12

add a comment |

up vote
1
down vote

If I understand the question correctly, yes. Each of the following is OK, though not necessarily efficient:

SELECT ...

   FROM ( ( SELECT ... ) UNION ( SELECT ... ) ) AS x



SELECT ...

   FROM a

   JOIN ( ( SELECT ... ) UNION ( SELECT ... ) ) AS x ON ...



SELECT ...

   FROM a

   LEFT JOIN ( ( SELECT ... ) UNION ( SELECT ... ) ) AS x ON ...



SELECT ...

   FROM ( ( SELECT ... ) UNION ( SELECT ... ) ) AS a

   JOIN ( ( SELECT ... ) UNION ( SELECT ... ) ) AS x ON ...

etc. (I may have added more parentheses than necessary.)

More UNION tips:

Yes, the number of columns needs to be the same.

The default column names come from the first SELECT.

If you have a constant string in a column of the first SELECT, that limits the length of the matching string of the other SELECTs. (Simply pad with blanks to 'fix' the problem.)

If appropriate, use UNION ALL do avoid the de-duping phase, thereby being faster than UNION, which is the same as UNION DISTINCT.

edited Nov 26 at 0:13

answered Nov 25 at 23:47

Rick James

39.9k22257

If I understand the question correctly, yes. Each of the following is OK, though not necessarily efficient:

SELECT ...

   FROM ( ( SELECT ... ) UNION ( SELECT ... ) ) AS x



SELECT ...

   FROM a

   JOIN ( ( SELECT ... ) UNION ( SELECT ... ) ) AS x ON ...



SELECT ...

   FROM a

   LEFT JOIN ( ( SELECT ... ) UNION ( SELECT ... ) ) AS x ON ...



SELECT ...

   FROM ( ( SELECT ... ) UNION ( SELECT ... ) ) AS a

   JOIN ( ( SELECT ... ) UNION ( SELECT ... ) ) AS x ON ...

etc. (I may have added more parentheses than necessary.)

More UNION tips:

Yes, the number of columns needs to be the same.

The default column names come from the first SELECT.

If you have a constant string in a column of the first SELECT, that limits the length of the matching string of the other SELECTs. (Simply pad with blanks to 'fix' the problem.)

If appropriate, use UNION ALL do avoid the de-duping phase, thereby being faster than UNION, which is the same as UNION DISTINCT.

edited Nov 26 at 0:13

answered Nov 25 at 23:47

Rick James

39.9k22257

edited Nov 26 at 0:13

answered Nov 25 at 23:47

Rick James

39.9k22257

answered Nov 25 at 23:47

Rick James

39.9k22257

answered Nov 25 at 23:47

Rick James

39.9k22257

@Rick the last 2 queries are equivalent. The ORDER BY is applied to the whole result set in both of them: dbfiddle.uk/…
– ypercubeᵀᴹ
Nov 25 at 23:58

1

@ypercubeᵀᴹ - Geez, I'm only a decade out of step -- bugs.mysql.com/bug.php?id=27848 "fixed" that in 2008 (5.0.56, 5.1.23). Thanks for rattling my cage.
– Rick James
Nov 26 at 0:12

add a comment |

@Rick the last 2 queries are equivalent. The ORDER BY is applied to the whole result set in both of them: dbfiddle.uk/…
– ypercubeᵀᴹ
Nov 25 at 23:58

1

@ypercubeᵀᴹ - Geez, I'm only a decade out of step -- bugs.mysql.com/bug.php?id=27848 "fixed" that in 2008 (5.0.56, 5.1.23). Thanks for rattling my cage.
– Rick James
Nov 26 at 0:12

@Rick the last 2 queries are equivalent. The ORDER BY is applied to the whole result set in both of them: dbfiddle.uk/…
– ypercubeᵀᴹ
Nov 25 at 23:58

@ypercubeᵀᴹ - Geez, I'm only a decade out of step -- bugs.mysql.com/bug.php?id=27848 "fixed" that in 2008 (5.0.56, 5.1.23). Thanks for rattling my cage.
– Rick James
Nov 26 at 0:12

add a comment |

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