abonnel-siteweb/data/pages/informatique/langage/sql/trouver-des-doublons.txt

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====== Trouver les doublons ======
{{ :informatique:langage:sql:sql_table_records.jpg?nolink&75x75|Trouver des doublons en SQL}}
~~NOTOC~~
<panel type="default" title="Code SQL">
<code SQL [enable_line_numbers="true", start_line_numbers_at="1"]>
SELECT COUNT(*) AS nbr_doublon, champ1, champ2, champ3
FROM table
GROUP BY champ1, champ2, champ3
HAVING COUNT(*) > 1
</code>
</panel>
<panel type="default" title="Code SQL">
<code SQL [enable_line_numbers="true", start_line_numbers_at="1"]>
SELECT DISTINCT *
FROM table t1
WHERE EXISTS (
SELECT *
FROM table t2
WHERE t1.ID <> t2.ID
AND t1.champ1 = t2.champ1
AND t1.champ2 = t2.champ2
AND t1.champ3 = t2.champ3 )
</code>
</panel>