Object
A statement represents a prepared-but-unexecuted SQL query. It will rarely (if ever) be instantiated directly by a client, and is most often obtained via the Database#prepare method.
Create a new statement attached to the given Database instance, and which encapsulates the given SQL text. If the text contains more than one statement (i.e., separated by semicolons), then the remainder property will be set to the trailing text.
# File lib/sqlite/statement.rb, line 53 def initialize( db, sql ) @db = db @statement = ParsedStatement.new( sql ) @remainder = @statement.trailing.strip @sql = @statement.to_s end
Binds value to the named (or positional) placeholder. If param is a Fixnum, it is treated as an index for a positional placeholder. Otherwise it is used as the name of the placeholder to bind to.
See also bind_params.
# File lib/sqlite/statement.rb, line 82 def bind_param( param, value ) @statement.bind_param( param, value ) end
Binds the given variables to the corresponding placeholders in the SQL text.
See Database#execute for a description of the valid placeholder syntaxes.
Example:
stmt = db.prepare( "select * from table where a=? and b=?" ) stmt.bind_params( 15, "hello" )
See also execute, bind_param, Statement#bind_param, and Statement#bind_params.
# File lib/sqlite/statement.rb, line 73 def bind_params( *bind_vars ) @statement.bind_params( *bind_vars ) end
Return an array of the column names for this statement. Note that this may execute the statement in order to obtain the metadata; this makes it a (potentially) expensive operation.
# File lib/sqlite/statement.rb, line 149 def columns get_metadata unless @columns return @columns end
Execute the statement. This creates a new ResultSet object for the statement's virtual machine. If a block was given, the new ResultSet will be yielded to it and then closed; otherwise, the ResultSet will be returned. In that case, it is the client's responsibility to close the ResultSet.
Any parameters will be bound to the statement using bind_params.
Example:
stmt = db.prepare( "select * from table" ) stmt.execute do |result| ... end
See also bind_params, execute!.
# File lib/sqlite/statement.rb, line 102 def execute( *bind_vars ) bind_params *bind_vars unless bind_vars.empty? results = ResultSet.new( @db, @statement.to_s ) if block_given? begin yield results ensure results.close end else return results end end
Execute the statement. If no block was given, this returns an array of rows returned by executing the statement. Otherwise, each row will be yielded to the block and then closed.
Any parameters will be bound to the statement using bind_params.
Example:
stmt = db.prepare( "select * from table" ) stmt.execute! do |row| ... end
See also bind_params, execute.
# File lib/sqlite/statement.rb, line 131 def execute!( *bind_vars ) result = execute( *bind_vars ) rows = [] unless block_given? while row = result.next if block_given? yield row else rows << row end end rows ensure result.close if result end
Return an array of the data types for each column in this statement. Note that this may execute the statement in order to obtain the metadata; this makes it a (potentially) expensive operation.
# File lib/sqlite/statement.rb, line 157 def types get_metadata unless @types return @types end
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