Module: TSqlMethods

Included in:
JdbcSpec::CacheDB, JdbcSpec::MsSQL
Defined in:
lib/jdbc_adapter/tsql_helper.rb

Overview

Common methods for handling TSQL databases.

Instance Method Summary collapse

Instance Method Details

#add_limit_offset!(sql, options) ⇒ Object 



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# File 'lib/jdbc_adapter/tsql_helper.rb', line 26

def add_limit_offset!(sql, options)
  if options[:limit] and options[:offset]
    total_query = sql.gsub(/\bSELECT(\s+DISTINCT)?\b/i, "SELECT\\1 TOP 1000000000")
    if options[:order] && sql =~ /DISTINCT/
      # SELECT DISTINCT cannot have order by unless order by appears in select,
      # You also cannot do a select distinct/order by in a subselect, so we need to
      # just chop the order by to prevent an error generating TotalRows
      total_query.gsub!(/ORDER BY #{options[:order]}/, '')
      sql.gsub!(/\bSELECT\s+(.*)\s+FROM\b/i, "SELECT \\1,#{options[:order].split.first} FROM")
    end
    total_rows = select_all("SELECT count(*) as TotalRows from (#{total_query}) tally")[0]["TotalRows"].to_i
    if (options[:limit] + options[:offset]) >= total_rows
      options[:limit] = (total_rows - options[:offset] >= 0) ? (total_rows - options[:offset]) : 0
    end
    sql.sub!(/^\s*SELECT(\s+DISTINCT)?/i, "SELECT * FROM (SELECT TOP #{options[:limit]} * FROM (SELECT\\1 TOP #{options[:limit] + options[:offset]} ")
    sql << ") AS tmp1"
    if options[:order]
      options[:order] = options[:order].split(',').map do |field|
        parts = field.split(" ")
        if options[:order] && sql =~ /DISTINCT/
          tc = parts[1]
        else
          tc = parts[0]
        end
        if sql =~ /\.\[/ and tc =~ /\./ # if column quoting used in query
          tc.gsub!(/\./, '\\.\\[')
          tc << '\\]'
        end
        if sql =~ /#{tc} AS (t\d_r\d\d?)/
          parts[0] = $1
        end
        parts.join(' ')
      end.join(', ')
      sql << " ) AS tmp2"
    else
      sql << " ) AS tmp2"
    end
  elsif sql !~ /^\s*SELECT (@@|COUNT\()/i
    sql.sub!(/^\s*SELECT(\s+DISTINCT)?/i) do
      "SELECT#{$1} TOP #{options[:limit]}"
    end unless options[:limit].nil?
  end
end

#modify_types(tp) ⇒ Object

:nodoc:



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# File 'lib/jdbc_adapter/tsql_helper.rb', line 4

def modify_types(tp) #:nodoc:
  tp[:primary_key] = "int NOT NULL IDENTITY(1, 1) PRIMARY KEY"
  tp[:integer][:limit] = nil
  tp[:boolean] = {:name => "bit"}
  tp[:binary] = { :name => "image"}
  tp
end

#type_to_sql(type, limit = nil, precision = nil, scale = nil) ⇒ Object

:nodoc:



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# File 'lib/jdbc_adapter/tsql_helper.rb', line 12

def type_to_sql(type, limit = nil, precision = nil, scale = nil) #:nodoc:
  return super unless type.to_s == 'integer'
  
  if limit.nil? || limit == 4
    'int'
  elsif limit == 2
    'smallint'
  elsif limit == 1
    'tinyint'
  else
    'bigint'
  end
end