Count rows - judgment result in the query

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Count rows - judgment result in the query

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#1 by (2 votes)

1

I need to count the rows that result in this statement (it works correctly and I know it returns a single value):

SELECT comp.descripcion 
FROM componente AS comp, pieza AS pza, pieza_equipo AS pzaequip, equipos AS equip 
WHERE comp.codigo = pza.codigo_componente AND 
pza.codigo = pzaequip.codigo_pieza AND 
pzaequip.codigo_equipo = equip.codigo AND 
comp.familia = 'CAJA' AND 
equip.codigo = 'eq_1101'

It will always return a row or none, that's what I'm interested in knowing.

mysql select

asked by aidamf 16.04.2018 в 18:11

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1 answer

PHP associative arrays Disable a list group

score 2 · Answer 1

You can use SQL_CALC_FOUND_ROWS like this:

SELECT SQL_CALC_FOUND_ROWS comp.descripcion 
FROM componente AS comp, pieza AS pza, pieza_equipo AS pzaequip, equipos AS equip 
WHERE comp.codigo = pza.codigo_componente AND 
pza.codigo = pzaequip.codigo_pieza AND 
pzaequip.codigo_equipo = equip.codigo AND 
comp.familia = 'CAJA' AND 
equip.codigo = 'eq_1101'

Then to know how many rows are returned by your query run:

SELECT FOUND_ROWS();