Class: Mysql::Stmt

Inherits:
Object
  • Object
show all
Defined in:
lib/ffi-mysql/stmt.rb,
lib/ffi-mysql/constants.rb

Overview

A MySQL statement.

Constant Summary collapse

CURSOR_TYPE_NO_CURSOR =

Cursor type

0
CURSOR_TYPE_READ_ONLY = 
1
NO_DATA = 
100
DATA_TRUNCATED = 
101

Instance Method Summary collapse

Constructor Details

#initialize(mysql) ⇒ Stmt

Returns a new instance of Stmt.

Raises:



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# File 'lib/ffi-mysql/stmt.rb', line 169

def initialize( mysql )
    @mysql = mysql
    @stmt = C::mysql_stmt_init(mysql)
    @params = []
    raise Error, error_msg if @stmt.nil? or @stmt.null?
    ObjectSpace.define_finalizer( self, Stmt.finalizer(@stmt) )

    _true = FFI::MemoryPointer.new(:int)
    _true.write_int(1)
    if C::mysql_stmt_attr_set(@stmt, :update_max_length, _true) != 0
        raise Error, error_msg
    end
end

Instance Method Details

#affected_rows ⇒ Integer

Returns the number of rows changed by the latest execution of this statement.

Returns:

  • (Integer) —

    the number of rows changed by the latest execution of this statement

Raises:



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# File 'lib/ffi-mysql/stmt.rb', line 318

def affected_rows
    raise Error, "Statment already closed" unless @stmt
    C::mysql_stmt_affected_rows(@stmt)
end

#bind_result(*args) ⇒ self

Associated output columns with buffer.

Parameters:

  • classes (Class) —

    of the result columns like Fixnum, String, …

Returns:

  • (self)

Raises:



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# File 'lib/ffi-mysql/stmt.rb', line 265

def bind_result(*args)
    raise Error, "Statment already closed" unless @stmt
    if args.size != @result_binds.size
        raise Error, "result value count (#{@result_binds.size}) != number of arguments (#{args.size})"
    end

    fields = @result.fetch_fields
    @result_binds.each_with_index do |bind, i|
        bind.set_bind_result( args[i], fields[i] )
        if C::mysql_stmt_bind_result( @stmt, @result_binds_ary ) != 0
            raise Error, error_msg
        end
    end
    self
end

#close ⇒ Object

Closes the statement.



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# File 'lib/ffi-mysql/stmt.rb', line 184

def close
    C::mysql_stmt_close(@stmt)
    @stmt = nil
    ObjectSpace.undefine_finalizer(self)
end

#data_seek(offset) ⇒ self

Seeks to an arbitrary row in the result set.

Parameters:

  • the (offset) —

    row to seek to

Returns:

  • (self)

Raises:



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# File 'lib/ffi-mysql/stmt.rb', line 309

def data_seek( offset )
    raise Error, "Statment already closed" unless @stmt
    C::mysql_stmt_data_seek( @stmt, offset )
    self
end

#each {|Array| ... } ⇒ Object

Iterates over all rows in this result set.

Yields:

  • (Array) —

    Called once for each row in this result set

See Also:

  • fetch_row


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# File 'lib/ffi-mysql/stmt.rb', line 300

def each
    while row = fetch
        yield row
    end
end

#execute(*args) ⇒ self

Executes the statement.

Parameters:

  • args —

    statement parameters

Returns:

  • (self)

Raises:



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# File 'lib/ffi-mysql/stmt.rb', line 224

def execute(*args)
    raise Error, "Statment already closed" unless @stmt
    if args.size != @param_binds.size
        raise Error, "param_count(#{@param_binds.size}) != number of arguments(#{args.size})"
    end

    free_result
    unless @param_binds.empty?
        @param_binds.each_with_index do |bind, i|
            bind.set_param args[i]
        end
        if C::mysql_stmt_bind_param(@stmt, @param_binds_ary) != 0
            raise Error, error_msg
        end
    end

    if C::mysql_stmt_execute(@stmt) != 0
        raise Error, error_msg
    end

    if @result
        if C::mysql_stmt_store_result(@stmt) != 0
            raise Error, error_msg
        end

        fields = @result.fetch_fields
        @result_binds.each_with_index do |bind, i|
            bind.set_result fields[i]
        end

        if C::mysql_stmt_bind_result(@stmt, @result_binds_ary) != 0
            raise Error, error_msg
        end
    end

    self
end

#fetch ⇒ Array

Returns the next row.

Returns:

  • (Array) —

    the next row.

Raises:



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# File 'lib/ffi-mysql/stmt.rb', line 282

def fetch
    raise Error, "Statment already closed" unless @stmt
    r = C::mysql_stmt_fetch(@stmt)
    case r
    when NO_DATA
        nil
    when DATA_TRUNCATED
        raise Error, "unexpectedly data truncated"
    when 1
        raise Error, error_msg
    else
        @result_binds.map{|bind| bind.value}
    end
end

#field_count ⇒ Integer

Returns the number of columns of this statement.

Returns:

  • (Integer) —

    the number of columns of this statement

Raises:



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# File 'lib/ffi-mysql/stmt.rb', line 324

def field_count
    raise Error, "Statment already closed" unless @stmt
    C::mysql_stmt_field_count(@stmt)
end

#free_result ⇒ self

Frees the current result of this statement.

Returns:

  • (self)

Raises:



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# File 'lib/ffi-mysql/stmt.rb', line 331

def free_result
    raise Error, "Statment already closed" unless @stmt
    if C::mysql_stmt_free_result(@stmt) != 0
        raise Error, error_msg
    end
end

#insert_id ⇒ Integer

Returns the value of an auto-increment column of the last INSERT or UPDATE statement.

Returns:

  • (Integer) —

    the value of an auto-increment column of the last INSERT or UPDATE statement

Raises:



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# File 'lib/ffi-mysql/stmt.rb', line 380

def insert_id
    raise Error, "Statment already closed" unless @stmt
    C::mysql_stmt_insert_id(@stmt)
end

#num_rows ⇒ Integer

Returns the number of rows of this statement.

Returns:

  • (Integer) —

    the number of rows of this statement

Raises:



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# File 'lib/ffi-mysql/stmt.rb', line 339

def num_rows
    raise Error, "Statment already closed" unless @stmt
    C::mysql_stmt_num_rows(@stmt)
end

#param_count ⇒ Integer

Returns the number of parameters of this statement.

Returns:

  • (Integer) —

    the number of parameters of this statement

Raises:



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# File 'lib/ffi-mysql/stmt.rb', line 345

def param_count
    raise Error, "Statment already closed" unless @stmt
    C::mysql_stmt_param_count(@stmt)
end

#prepare(stmt) ⇒ self

Preparse the statement

Parameters:

  • stmt (String) —

    the SQL statement

Returns:

  • (self)

Raises:



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# File 'lib/ffi-mysql/stmt.rb', line 193

def prepare(stmt)
    raise Error, "Statment already closed" unless @stmt
    if C::mysql_stmt_prepare(@stmt, stmt, stmt.size) != 0
        raise Error, error_msg
    end

    nparams = param_count
    @param_binds_ary = FFI::MemoryPointer.new C::Bind, nparams, true
    @param_binds = (0...nparams).map {|i|
        C::Bind.new(FFI::Pointer.new(C::Bind, @param_binds_ary.address + i * C::Bind.size))
    }

    if @result = result_metadata
        fields = @result.fetch_fields
        @result_binds_ary = FFI::MemoryPointer.new C::Bind, fields.size, true
        @result_binds = (0...fields.size).map{|i|
            bind = C::Bind.new(FFI::Pointer.new(C::Bind, @result_binds_ary.address + i * C::Bind.size))
            bind.prepare_result( fields[i] )
            bind
        }
    else
        @result_binds_ary = nil
        @result_binds = []
    end

    self
end

#result_metadata ⇒ Result

Returns the result metadata of the current statement.

Returns:

  • (Result) —

    the result metadata of the current statement

Raises:



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# File 'lib/ffi-mysql/stmt.rb', line 365

def result_metadata
    raise Error, "Statment already closed" unless @stmt
    result = C::mysql_stmt_result_metadata(@stmt)
    if result.nil? or result.null?
        if C::mysql_stmt_errno(@stmt) != 0
            raise Error, error_msg
        end
        nil
    else
        Result.new(@mysql, result)
    end
end

#row_seek(offset) ⇒ Integer

Sets the position of the row cursor.

Parameters:

  • offset (Integer) —

    the new position of the row cursor

Returns:

  • (Integer) —

    the former position of the row cursor

Raises:



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# File 'lib/ffi-mysql/stmt.rb', line 359

def row_seek( offset )
    raise Error, "Statment already closed" unless @stmt
    C::mysql_stmt_row_seek(@stmt, offset)
end

#row_tell ⇒ Integer

Returns the number of the current row of the most recent result.

Returns:

  • (Integer) —

    the number of the current row of the most recent result

Raises:



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# File 'lib/ffi-mysql/stmt.rb', line 351

def row_tell
    raise Error, "Statment already closed" unless @stmt
    C::mysql_stmt_row_tell(@stmt)
end

#sqlstate ⇒ String

Returns the SQLSTATE error code for this statement.

Returns:

  • (String) —

    the SQLSTATE error code for this statement

Raises:



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# File 'lib/ffi-mysql/stmt.rb', line 386

def sqlstate
    raise Error, "Statment already closed" unless @stmt
    C::mysql_stmt_sqlstate(@stmt)
end