Module: ArJdbc::Sybase

Defined in:
lib/arjdbc/sybase/adapter.rb

Instance Method Summary collapse

Instance Method Details

#add_limit_offset!(sql, options) ⇒ Object

:nodoc:



3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
 
# File 'lib/arjdbc/sybase/adapter.rb', line 3

def add_limit_offset!(sql, options) # :nodoc:
  @limit = options[:limit]
  @offset = options[:offset]
  if use_temp_table?
    # Use temp table to hack offset with Sybase
    sql.sub!(/ FROM /i, ' INTO #artemp FROM ')
  elsif zero_limit?
    # "SET ROWCOUNT 0" turns off limits, so we havesy
    # to use a cheap trick.
    if sql =~ /WHERE/i
      sql.sub!(/WHERE/i, 'WHERE 1 = 2 AND ')
    elsif sql =~ /ORDER\s+BY/i
      sql.sub!(/ORDER\s+BY/i, 'WHERE 1 = 2 ORDER BY')
    else
      sql << 'WHERE 1 = 2'
    end
  end
end

#modify_types(types) ⇒ Object

:nodoc:



34
35
36
37
38
39
40
41
 
# File 'lib/arjdbc/sybase/adapter.rb', line 34

def modify_types(types) # :nodoc:
  super(types)
  types[:primary_key] = "NUMERIC(22,0) IDENTITY PRIMARY KEY"
  types[:integer][:limit] = nil
  types[:boolean] = {:name => "bit"}
  types[:binary] = {:name => "image"}
  types
end

#remove_index(table_name, options = {}) ⇒ Object 



43
44
45
 
# File 'lib/arjdbc/sybase/adapter.rb', line 43

def remove_index(table_name, options = {})
  execute "DROP INDEX #{table_name}.#{index_name(table_name, options)}"
end

#use_temp_table? ⇒ Boolean

If limit is not set at all, we can ignore offset; if limit is set but offset is zero, use normal select with simple SET ROWCOUNT. Thus, only use the temp table if limit is set and offset > 0.

Returns:

  • (Boolean) 


26
27
28
 
# File 'lib/arjdbc/sybase/adapter.rb', line 26

def use_temp_table?
  !@limit.nil? && !@offset.nil? && @offset > 0
end

#zero_limit? ⇒ Boolean

Returns:

  • (Boolean) 


30
31
32
 
# File 'lib/arjdbc/sybase/adapter.rb', line 30

def zero_limit?
  !@limit.nil? && @limit == 0
end