Module: Sequel::Dataset::PreparedStatementMethods
- Defined in:
- lib/sequel/dataset/prepared_statements.rb
Overview
Backbone of the prepared statement support. Grafts bind variable support into datasets by hijacking #literal and using placeholders. By default, emulates prepared statements and bind variables by taking the hash of bind variables and directly substituting them into the query, which works on all databases, as it is no different from using the dataset without bind variables.
Instance Method Summary collapse
-
#call(bind_vars = {}, &block) ⇒ Object
Sets the prepared_args to the given hash and runs the prepared statement.
-
#columns ⇒ Object
Send the columns to the original dataset, as calling it on the prepared statement can cause problems.
-
#delayed_evaluation_sql_append(sql, delay) ⇒ Object
Disallow use of delayed evaluations in prepared statements.
-
#inspect ⇒ Object
Programmer friendly string showing this is a prepared statement, with the prepared SQL it represents (which in general won't have substituted variables).
-
#literal_symbol_append(sql, v) ⇒ Object
Changes the values of symbols if they start with $ and prepared_args is present.
-
#log_sql ⇒ Object
Whether to log the full SQL query.
-
#orig_dataset ⇒ Object
The dataset that created this prepared statement.
-
#prepare ⇒ Object
Raise an error if attempting to call prepare on an already prepared statement.
-
#prepared_args ⇒ Object
The array/hash of bound variable placeholder names.
-
#prepared_modify_values ⇒ Object
The argument to supply to insert and update, which may use placeholders specified by prepared_args.
-
#prepared_sql ⇒ Object
Returns the SQL for the prepared statement, depending on the type of the statement and the prepared_modify_values.
-
#prepared_type ⇒ Object
The type of prepared statement, should be one of :select, :first, :insert, :update, or :delete.
Instance Method Details
#call(bind_vars = {}, &block) ⇒ Object
Sets the prepared_args to the given hash and runs the prepared statement.
109 110 111 |
# File 'lib/sequel/dataset/prepared_statements.rb', line 109 def call(bind_vars={}, &block) bind(bind_vars).run(&block) end |
#columns ⇒ Object
Send the columns to the original dataset, as calling it on the prepared statement can cause problems.
122 123 124 |
# File 'lib/sequel/dataset/prepared_statements.rb', line 122 def columns orig_dataset.columns end |
#delayed_evaluation_sql_append(sql, delay) ⇒ Object
Disallow use of delayed evaluations in prepared statements.
127 128 129 130 |
# File 'lib/sequel/dataset/prepared_statements.rb', line 127 def delayed_evaluation_sql_append(sql, delay) raise Error, "delayed evaluations cannot be used in prepared statements" if @opts[:no_delayed_evaluations] super end |
#inspect ⇒ Object
Programmer friendly string showing this is a prepared statement, with the prepared SQL it represents (which in general won't have substituted variables).
173 174 175 |
# File 'lib/sequel/dataset/prepared_statements.rb', line 173 def inspect "<#{visible_class_name}/PreparedStatement #{prepared_sql.inspect}>" end |
#literal_symbol_append(sql, v) ⇒ Object
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.
157 158 159 160 161 162 163 164 165 166 167 168 |
# File 'lib/sequel/dataset/prepared_statements.rb', line 157 def literal_symbol_append(sql, v) if @opts[:bind_vars] and match = /\A\$(.*)\z/.match(v.to_s) s = match[1].to_sym if prepared_arg?(s) literal_append(sql, prepared_arg(s)) else sql << v.to_s end else super end end |
#log_sql ⇒ Object
Whether to log the full SQL query. By default, just the prepared statement name is generally logged on adapters that support native prepared statements.
81 82 83 |
# File 'lib/sequel/dataset/prepared_statements.rb', line 81 def log_sql @opts[:log_sql] end |
#orig_dataset ⇒ Object
The dataset that created this prepared statement.
97 98 99 |
# File 'lib/sequel/dataset/prepared_statements.rb', line 97 def orig_dataset @opts[:orig_dataset] end |
#prepare ⇒ Object
Raise an error if attempting to call prepare on an already prepared statement.
115 116 117 118 |
# File 'lib/sequel/dataset/prepared_statements.rb', line 115 def prepare(*) raise Error, "cannot prepare an already prepared statement" unless allow_preparing_prepared_statements? super end |
#prepared_args ⇒ Object
The array/hash of bound variable placeholder names.
92 93 94 |
# File 'lib/sequel/dataset/prepared_statements.rb', line 92 def prepared_args @opts[:prepared_args] end |
#prepared_modify_values ⇒ Object
The argument to supply to insert and update, which may use placeholders specified by prepared_args
103 104 105 |
# File 'lib/sequel/dataset/prepared_statements.rb', line 103 def prepared_modify_values @opts[:prepared_modify_values] end |
#prepared_sql ⇒ Object
Returns the SQL for the prepared statement, depending on the type of the statement and the prepared_modify_values.
134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 |
# File 'lib/sequel/dataset/prepared_statements.rb', line 134 def prepared_sql case prepared_type when :select, :all, :each # Most common scenario, so listed first. select_sql when :first clone(:limit=>1).select_sql when :insert_select insert_select_sql(*prepared_modify_values) when :insert, :insert_pk insert_sql(*prepared_modify_values) when :update update_sql(*prepared_modify_values) when :delete delete_sql else select_sql end end |
#prepared_type ⇒ Object
The type of prepared statement, should be one of :select, :first, :insert, :update, or :delete
87 88 89 |
# File 'lib/sequel/dataset/prepared_statements.rb', line 87 def prepared_type @opts[:prepared_type] end |