Class: Sequel::ODBC::MSSQL::Dataset

Inherits:
ODBC::Dataset
  • Object
show all
Defined in:
lib/sequel/adapters/odbc_mssql.rb

Instance Method Summary collapse

Instance Method Details

#nolock ⇒ Object

Allows you to do .nolock on a query



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# File 'lib/sequel/adapters/odbc_mssql.rb', line 19

def nolock
  clone_merge(:with => "(NOLOCK)")
end

#select_sql(opts = nil) ⇒ Object Also known as: sql

Formats a SELECT statement using the given options and the dataset options.



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# File 'lib/sequel/adapters/odbc_mssql.rb', line 25

def select_sql(opts = nil)
  opts = opts ? @opts.merge(opts) : @opts

  if sql = opts[:sql]
    return sql
  end

  # ADD TOP to SELECT string for LIMITS
  if limit = opts[:limit]
    top = "TOP #{limit} "
    raise SequelError, "Offset not supported" if opts[:offset]
  end

  columns = opts[:select]
  select_columns = columns ? column_list(columns) : WILDCARD

  if distinct = opts[:distinct]
    distinct_clause = distinct.empty? ? "DISTINCT" : "DISTINCT ON (#{column_list(distinct)})"
    sql = "SELECT #{top}#{distinct_clause} #{select_columns}"
  else
    sql = "SELECT #{top}#{select_columns}"
  end

  if opts[:from]
    sql << " FROM #{source_list(opts[:from])}"
  end

  # ADD WITH to SELECT string for NOLOCK
  if with = opts[:with]
    sql << " WITH #{with}"
  end

  if join = opts[:join]
    sql << join
  end

  if where = opts[:where]
    sql << " WHERE #{where}"
  end

  if group = opts[:group]
    sql << " GROUP BY #{column_list(group)}"
  end

  if order = opts[:order]
    sql << " ORDER BY #{column_list(order)}"
  end

  if having = opts[:having]
    sql << " HAVING #{having}"
  end

  if union = opts[:union]
    sql << (opts[:union_all] ? \
      " UNION ALL #{union.sql}" : " UNION #{union.sql}")
  elsif intersect = opts[:intersect]
    sql << (opts[:intersect_all] ? \
      " INTERSECT ALL #{intersect.sql}" : " INTERSECT #{intersect.sql}")
  elsif except = opts[:except]
    sql << (opts[:except_all] ? \
      " EXCEPT ALL #{except.sql}" : " EXCEPT #{except.sql}")
  end

  sql
end