Module Sequel::Dataset::PreparedStatementMethods
In: lib/sequel/dataset/prepared_statements.rb
lib/sequel/adapters/sqlite.rb
lib/sequel/adapters/postgres.rb
lib/sequel/adapters/jdbc.rb

Use JDBC PreparedStatements instead of emulated ones. Statements created using prepare are cached at the connection level to allow reuse. This also supports bind variables by using unnamed prepared statements created using call.

Methods

call   call   columns   inspect   literal_symbol_append   prepared_sql   run  

Included Modules

BindArgumentMethods BindArgumentMethods Sequel::Dataset::UnnumberedArgumentMapper

Constants

PLACEHOLDER_RE = /\A\$(.*)\z/

Attributes

orig_dataset  [RW]  The dataset that created this prepared statement.
prepared_args  [RW]  The array/hash of bound variable placeholder names.
prepared_modify_values  [RW]  The argument to supply to insert and update, which may use placeholders specified by prepared_args
prepared_type  [RW]  The type of prepared statement, should be one of :select, :first, :insert, :update, or :delete

Public Instance methods

call(bind_vars={}, &block)

Sets the prepared_args to the given hash and runs the prepared statement.

[Source]

    # File lib/sequel/dataset/prepared_statements.rb, line 65
65:       def call(bind_vars={}, &block)
66:         bind(bind_vars).run(&block)
67:       end
call(*)

Raise a more obvious error if you attempt to call a unnamed prepared statement.

[Source]

     # File lib/sequel/adapters/postgres.rb, line 560
560:           def call(*)
561:             raise Error, "Cannot call prepared statement without a name" if prepared_statement_name.nil?
562:             super
563:           end
columns()

Send the columns to the original dataset, as calling it on the prepared statement can cause problems.

[Source]

    # File lib/sequel/dataset/prepared_statements.rb, line 71
71:       def columns
72:         orig_dataset.columns
73:       end
inspect()

Programmer friendly string showing this is a prepared statement, with the prepared SQL it represents (which in general won‘t have substituted variables).

[Source]

     # File lib/sequel/dataset/prepared_statements.rb, line 113
113:       def inspect
114:         "<#{self.class.name}/PreparedStatement #{prepared_sql.inspect}>"
115:       end
literal_symbol_append(sql, v)

Changes the values of symbols if they start with $ and prepared_args is present. If so, they are considered placeholders, and they are substituted using prepared_arg.

[Source]

     # File lib/sequel/dataset/prepared_statements.rb, line 97
 97:       def literal_symbol_append(sql, v)
 98:         if @opts[:bind_vars] and match = PLACEHOLDER_RE.match(v.to_s)
 99:           s = match[1].to_sym
100:           if prepared_arg?(s)
101:             literal_append(sql, prepared_arg(s))
102:           else
103:             sql << v.to_s
104:           end
105:         else
106:           super
107:         end
108:       end
prepared_sql()

Returns the SQL for the prepared statement, depending on the type of the statement and the prepared_modify_values.

[Source]

    # File lib/sequel/dataset/prepared_statements.rb, line 77
77:       def prepared_sql
78:         case @prepared_type
79:         when :select, :all
80:           select_sql
81:         when :first
82:           clone(:limit=>1).select_sql
83:         when :insert_select
84:           returning.insert_sql(*@prepared_modify_values)
85:         when :insert
86:           insert_sql(*@prepared_modify_values)
87:         when :update
88:           update_sql(*@prepared_modify_values)
89:         when :delete
90:           delete_sql
91:         end
92:       end

Protected Instance methods

run(&block)

Run the method based on the type of prepared statement, with :select running all to get all of the rows, and the other types running the method with the same name as the type.

[Source]

     # File lib/sequel/dataset/prepared_statements.rb, line 122
122:       def run(&block)
123:         case @prepared_type
124:         when :select, :all
125:           all(&block)
126:         when :insert_select
127:           with_sql(prepared_sql).first
128:         when :first
129:           first
130:         when :insert
131:           insert(*@prepared_modify_values)
132:         when :update
133:           update(*@prepared_modify_values)
134:         when :delete
135:           delete
136:         end
137:       end

[Validate]