Module: ActiveRecord::ConnectionAdapters::PostgreSQL::DatabaseStatements

Included in:
ActiveRecord::ConnectionAdapters::PostgreSQLAdapter
Defined in:
activerecord/lib/active_record/connection_adapters/postgresql/database_statements.rb

Constant Summary collapse

MONEY_COLUMN_TYPE_OID =

The internal PostgreSQL identifier of the money data type.

790
BYTEA_COLUMN_TYPE_OID =

The internal PostgreSQL identifier of the BYTEA data type.

17

Instance Method Summary collapse

Instance Method Details

#begin_db_transactionObject

Begins a transaction.


149
150
151
# File 'activerecord/lib/active_record/connection_adapters/postgresql/database_statements.rb', line 149

def begin_db_transaction
  execute("BEGIN", "TRANSACTION")
end

#begin_isolated_db_transaction(isolation) ⇒ Object


153
154
155
156
# File 'activerecord/lib/active_record/connection_adapters/postgresql/database_statements.rb', line 153

def begin_isolated_db_transaction(isolation)
  begin_db_transaction
  execute "SET TRANSACTION ISOLATION LEVEL #{transaction_isolation_levels.fetch(isolation)}"
end

#commit_db_transactionObject

Commits a transaction.


159
160
161
# File 'activerecord/lib/active_record/connection_adapters/postgresql/database_statements.rb', line 159

def commit_db_transaction
  execute("COMMIT", "TRANSACTION")
end

#exec_delete(sql, name = nil, binds = []) ⇒ Object Also known as: exec_update


110
111
112
# File 'activerecord/lib/active_record/connection_adapters/postgresql/database_statements.rb', line 110

def exec_delete(sql, name = nil, binds = [])
  execute_and_clear(sql, name, binds) { |result| result.cmd_tuples }
end

#exec_insert(sql, name = nil, binds = [], pk = nil, sequence_name = nil) ⇒ Object


130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
# File 'activerecord/lib/active_record/connection_adapters/postgresql/database_statements.rb', line 130

def exec_insert(sql, name = nil, binds = [], pk = nil, sequence_name = nil)
  if use_insert_returning? || pk == false
    super
  else
    result = exec_query(sql, name, binds)
    unless sequence_name
      table_ref = extract_table_ref_from_insert_sql(sql)
      if table_ref
        pk = primary_key(table_ref) if pk.nil?
        pk = suppress_composite_primary_key(pk)
        sequence_name = default_sequence_name(table_ref, pk)
      end
      return result unless sequence_name
    end
    last_insert_id_result(sequence_name)
  end
end

#exec_query(sql, name = "SQL", binds = [], prepare: false) ⇒ Object


97
98
99
100
101
102
103
104
105
106
107
108
# File 'activerecord/lib/active_record/connection_adapters/postgresql/database_statements.rb', line 97

def exec_query(sql, name = "SQL", binds = [], prepare: false)
  execute_and_clear(sql, name, binds, prepare: prepare) do |result|
    types = {}
    fields = result.fields
    fields.each_with_index do |fname, i|
      ftype = result.ftype i
      fmod  = result.fmod i
      types[fname] = get_oid_type(ftype, fmod, fname)
    end
    build_result(columns: fields, rows: result.values, column_types: types)
  end
end

#exec_rollback_db_transactionObject

Aborts a transaction.


164
165
166
# File 'activerecord/lib/active_record/connection_adapters/postgresql/database_statements.rb', line 164

def exec_rollback_db_transaction
  execute("ROLLBACK", "TRANSACTION")
end

#execute(sql, name = nil) ⇒ Object

Executes an SQL statement, returning a PG::Result object on success or raising a PG::Error exception otherwise. Note: the PG::Result object is manually memory managed; if you don't need it specifically, you may want consider the exec_query wrapper.


83
84
85
86
87
88
89
90
91
92
93
94
95
# File 'activerecord/lib/active_record/connection_adapters/postgresql/database_statements.rb', line 83

def execute(sql, name = nil)
  if preventing_writes? && write_query?(sql)
    raise ActiveRecord::ReadOnlyError, "Write query attempted while in readonly mode: #{sql}"
  end

  materialize_transactions

  log(sql, name) do
    ActiveSupport::Dependencies.interlock.permit_concurrent_loads do
      @connection.async_exec(sql)
    end
  end
end

#explain(arel, binds = []) ⇒ Object


7
8
9
10
# File 'activerecord/lib/active_record/connection_adapters/postgresql/database_statements.rb', line 7

def explain(arel, binds = [])
  sql = "EXPLAIN #{to_sql(arel, binds)}"
  PostgreSQL::ExplainPrettyPrinter.new.pp(exec_query(sql, "EXPLAIN", binds))
end

#query(sql, name = nil) ⇒ Object

Queries the database and returns the results in an Array-like object


60
61
62
63
64
65
66
67
68
# File 'activerecord/lib/active_record/connection_adapters/postgresql/database_statements.rb', line 60

def query(sql, name = nil) #:nodoc:
  materialize_transactions

  log(sql, name) do
    ActiveSupport::Dependencies.interlock.permit_concurrent_loads do
      result_as_array @connection.async_exec(sql)
    end
  end
end

#result_as_array(res) ⇒ Object

create a 2D array representing the result set


18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
# File 'activerecord/lib/active_record/connection_adapters/postgresql/database_statements.rb', line 18

def result_as_array(res) #:nodoc:
  # check if we have any binary column and if they need escaping
  ftypes = Array.new(res.nfields) do |i|
    [i, res.ftype(i)]
  end

  rows = res.values
  return rows unless ftypes.any? { |_, x|
    x == BYTEA_COLUMN_TYPE_OID || x == MONEY_COLUMN_TYPE_OID
  }

  typehash = ftypes.group_by { |_, type| type }
  binaries = typehash[BYTEA_COLUMN_TYPE_OID] || []
  monies   = typehash[MONEY_COLUMN_TYPE_OID] || []

  rows.each do |row|
    # unescape string passed BYTEA field (OID == 17)
    binaries.each do |index, _|
      row[index] = unescape_bytea(row[index])
    end

    # If this is a money type column and there are any currency symbols,
    # then strip them off. Indeed it would be prettier to do this in
    # PostgreSQLColumn.string_to_decimal but would break form input
    # fields that call value_before_type_cast.
    monies.each do |index, _|
      data = row[index]
      # Because money output is formatted according to the locale, there are two
      # cases to consider (note the decimal separators):
      #  (1) $12,345,678.12
      #  (2) $12.345.678,12
      case data
      when /^-?\D+[\d,]+\.\d{2}$/  # (1)
        data.gsub!(/[^-\d.]/, "")
      when /^-?\D+[\d.]+,\d{2}$/  # (2)
        data.gsub!(/[^-\d,]/, "").sub!(/,/, ".")
      end
    end
  end
end

#write_query?(sql) ⇒ Boolean

:nodoc:

Returns:

  • (Boolean)

75
76
77
# File 'activerecord/lib/active_record/connection_adapters/postgresql/database_statements.rb', line 75

def write_query?(sql) # :nodoc:
  !READ_QUERY.match?(sql)
end