Module | Sequel::Dataset::PreparedStatementMethods |
In: |
lib/sequel/dataset/prepared_statements.rb
lib/sequel/adapters/sqlite.rb |
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.
PLACEHOLDER_RE | = | /\A\$(.*)\z/ |
log_sql | [RW] | Whether to log the full SQL query. By default, just the prepared statement name is generally logged on adapters that support native prepared statements. |
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 |
Sets the prepared_args to the given hash and runs the prepared statement.
# File lib/sequel/dataset/prepared_statements.rb, line 69 69: def call(bind_vars={}, &block) 70: bind(bind_vars).run(&block) 71: end
Programmer friendly string showing this is a prepared statement, with the prepared SQL it represents (which in general won‘t have substituted variables).
# File lib/sequel/dataset/prepared_statements.rb, line 120 120: def inspect 121: "<#{visible_class_name}/PreparedStatement #{prepared_sql.inspect}>" 122: end
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.
# File lib/sequel/dataset/prepared_statements.rb, line 104 104: def literal_symbol_append(sql, v) 105: if @opts[:bind_vars] and match = PLACEHOLDER_RE.match(v.to_s) 106: s = match[1].to_sym 107: if prepared_arg?(s) 108: literal_append(sql, prepared_arg(s)) 109: else 110: sql << v.to_s 111: end 112: else 113: super 114: end 115: end
Returns the SQL for the prepared statement, depending on the type of the statement and the prepared_modify_values.
# File lib/sequel/dataset/prepared_statements.rb, line 81 81: def prepared_sql 82: case @prepared_type 83: when :select, :all, :each 84: # Most common scenario, so listed first. 85: select_sql 86: when :first 87: clone(:limit=>1).select_sql 88: when :insert_select 89: insert_select_sql(*@prepared_modify_values) 90: when :insert 91: insert_sql(*@prepared_modify_values) 92: when :update 93: update_sql(*@prepared_modify_values) 94: when :delete 95: delete_sql 96: else 97: select_sql 98: end 99: end
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.
# File lib/sequel/dataset/prepared_statements.rb, line 129 129: def run(&block) 130: case @prepared_type 131: when :select, :all 132: # Most common scenario, so listed first 133: all(&block) 134: when :each 135: each(&block) 136: when :insert_select 137: with_sql(prepared_sql).first 138: when :first 139: first 140: when :insert 141: insert(*@prepared_modify_values) 142: when :update 143: update(*@prepared_modify_values) 144: when :delete 145: delete 146: when Array 147: case @prepared_type.at(0) 148: when :map, :to_hash, :to_hash_groups 149: send(*@prepared_type, &block) 150: end 151: else 152: all(&block) 153: end 154: end