57 lines
2.3 KiB
Ruby
57 lines
2.3 KiB
Ruby
if defined?(ActiveRecord::ConnectionAdaptors::PostgreSQLAdaptor)
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module ActiveRecord
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module ConnectionAdapters
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class PostgreSQLAdapter
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def pk_and_sequence_for(table)
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# First try looking for a sequence with a dependency on the
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# given table's primary key.
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result = query(<<-end_sql, 'PK and serial sequence')[0]
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SELECT attr.attname, seq.relname
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FROM pg_class seq,
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pg_attribute attr,
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pg_depend dep,
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pg_namespace name,
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pg_constraint cons
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WHERE seq.oid = dep.objid
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AND seq.relkind = 'S'
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AND attr.attrelid = dep.refobjid
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AND attr.attnum = dep.refobjsubid
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AND attr.attrelid = cons.conrelid
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AND attr.attnum = cons.conkey[1]
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AND cons.contype = 'p'
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AND dep.classid = '"pg_class"'::regclass
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AND dep.refclassid = '"pg_class"'::regclass
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AND dep.refobjid = '#{quote_table_name(table)}'::regclass
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end_sql
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if result.nil? or result.empty?
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# If that fails, try parsing the primary key's default value.
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# Support the 7.x and 8.0 nextval('foo'::text) as well as
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# the 8.1+ nextval('foo'::regclass).
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result = query(<<-end_sql, 'PK and custom sequence')[0]
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SELECT attr.attname,
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CASE
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WHEN split_part(def.adsrc, '''', 2) ~ '.' THEN
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substr(split_part(def.adsrc, '''', 2),
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strpos(split_part(def.adsrc, '''', 2), '.')+1)
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ELSE split_part(def.adsrc, '''', 2)
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END
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FROM pg_class t
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JOIN pg_attribute attr ON (t.oid = attrelid)
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JOIN pg_attrdef def ON (adrelid = attrelid AND adnum = attnum)
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JOIN pg_constraint cons ON (conrelid = adrelid AND adnum = conkey[1])
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WHERE t.oid = '#{quote_table_name(table)}'::regclass
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AND cons.contype = 'p'
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AND def.adsrc ~* 'nextval'
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end_sql
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end
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# [primary_key, sequence]
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[result.first, result.last]
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rescue
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nil
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end
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end
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end
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end
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end
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