Module: Sequel::Postgres::AdapterMethods

Included in:
DataObjects::Postgres::AdapterMethods, JDBC::Postgres::AdapterMethods, Adapter
Defined in:
lib/sequel/lib/sequel/adapters/shared/postgres.rb

Overview

Methods shared by adapter/connection instances.

Constant Summary collapse

SELECT_CURRVAL = 
"SELECT currval('%s')".freeze
SELECT_CUSTOM_SEQUENCE = 
proc do |schema, table| <<-end_sql
  SELECT '"' || name.nspname || '".' || CASE  
      WHEN split_part(def.adsrc, '''', 2) ~ '.' THEN  
        substr(split_part(def.adsrc, '''', 2),  
               strpos(split_part(def.adsrc, '''', 2), '.')+1) 
      ELSE split_part(def.adsrc, '''', 2)  
    END
  FROM pg_class t
  JOIN pg_namespace  name ON (t.relnamespace = name.oid)
  JOIN pg_attribute  attr ON (t.oid = attrelid)
  JOIN pg_attrdef    def  ON (adrelid = attrelid AND adnum = attnum)
  JOIN pg_constraint cons ON (conrelid = adrelid AND adnum = conkey[1])
  WHERE cons.contype = 'p'
    AND def.adsrc ~* 'nextval'
    #{"AND name.nspname = '#{schema}'" if schema}
    AND t.relname = '#{table}'
end_sql
end
SELECT_PK = 
proc do |schema, table| <<-end_sql
  SELECT pg_attribute.attname
  FROM pg_class, pg_attribute, pg_index, pg_namespace
  WHERE pg_class.oid = pg_attribute.attrelid
    AND pg_class.relnamespace  = pg_namespace.oid
    AND pg_class.oid = pg_index.indrelid
    AND pg_index.indkey[0] = pg_attribute.attnum
    AND pg_index.indisprimary = 't'
    #{"AND pg_namespace.nspname = '#{schema}'" if schema}
    AND pg_class.relname = '#{table}'
end_sql
end
SELECT_SERIAL_SEQUENCE = 
proc do |schema, table| <<-end_sql
  SELECT  '"' || name.nspname || '".' || seq.relname || ''
  FROM pg_class seq, pg_attribute attr, pg_depend dep,
    pg_namespace name, pg_constraint cons
  WHERE seq.oid = dep.objid
    AND seq.relnamespace  = name.oid
    AND seq.relkind = 'S'
    AND attr.attrelid = dep.refobjid
    AND attr.attnum = dep.refobjsubid
    AND attr.attrelid = cons.conrelid
    AND attr.attnum = cons.conkey[1]
    AND cons.contype = 'p'
    #{"AND name.nspname = '#{schema}'" if schema}
    AND seq.relname = '#{table}'
end_sql
end

Instance Attribute Summary collapse

Instance Method Summary collapse

Instance Attribute Details

#db=(value) ⇒ Object (writeonly)

Sets the attribute db


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# File 'lib/sequel/lib/sequel/adapters/shared/postgres.rb', line 55

def db=(value)
  @db = value
end

#transaction_depth ⇒ Object

Depth of the current transaction on this connection, used to implement multi-level transactions with savepoints.


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# File 'lib/sequel/lib/sequel/adapters/shared/postgres.rb', line 107

def transaction_depth
  @transaction_depth
end

Instance Method Details

#apply_connection_settings ⇒ Object

Apply connection settings for this connection. Currently, turns standard_conforming_strings ON if Postgres.force_standard_strings is true.


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# File 'lib/sequel/lib/sequel/adapters/shared/postgres.rb', line 112

def apply_connection_settings
  if Postgres.force_standard_strings
    sql = "SET standard_conforming_strings = ON"
    @db.log_info(sql)    # This setting will only work on PostgreSQL 8.2 or greater
    # and we don't know the server version at this point, so
    # try it unconditionally and rescue any errors.

    execute(sql) rescue nil
  end
  if cmm = Postgres.client_min_messages
    sql = "SET client_min_messages = '#{cmm.to_s.upcase}'"
    @db.log_info(sql)
    execute(sql)
  end
end

#last_insert_id(sequence) ⇒ Object

Get the last inserted value for the given sequence.


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# File 'lib/sequel/lib/sequel/adapters/shared/postgres.rb', line 129

def last_insert_id(sequence)
  sql = SELECT_CURRVAL % sequence
  @db.log_info(sql)
  execute(sql) do |r|
    val = single_value(r)
    return val.to_i if val
  end
end

#primary_key(schema, table) ⇒ Object

Get the primary key for the given table.


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# File 'lib/sequel/lib/sequel/adapters/shared/postgres.rb', line 139

def primary_key(schema, table)
  sql = SELECT_PK[schema, table]
  @db.log_info(sql)
  execute(sql) do |r|
    return single_value(r)
  end
end

#sequence(schema, table) ⇒ Object

Get the primary key and sequence for the given table.


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# File 'lib/sequel/lib/sequel/adapters/shared/postgres.rb', line 148

def sequence(schema, table)
  sql = SELECT_SERIAL_SEQUENCE[schema, table]
  @db.log_info(sql)
  execute(sql) do |r|
    seq = single_value(r)
    return seq if seq
  end
  
  sql = SELECT_CUSTOM_SEQUENCE[schema, table]
  @db.log_info(sql)
  execute(sql) do |r|
    return single_value(r)
  end
end