Class: Flydata::SourcePostgresql::QueryBasedSync::DiffQueryGenerator
- Inherits:
-
Object
- Object
- Flydata::SourcePostgresql::QueryBasedSync::DiffQueryGenerator
- Defined in:
- lib/flydata/source_postgresql/query_based_sync/diff_query_generator.rb
Constant Summary collapse
- DEFAULT_LIMIT =
10000
- FETCH_RECORDS_SQL =
<<EOS SELECT %{columns} FROM %{table_name} WHERE %{where_clause} ORDER BY %{order_by_clause} LIMIT %{max_rows}; EOS
- TO_SID_WHERE_CLAUSE =
"txid_visible_in_snapshot(xmin::TEXT::BIGINT, '%{to_sid}')"
- FROM_SID_WHERE_CLAUSE =
"AND NOT txid_visible_in_snapshot(xmin::TEXT::BIGINT, '%{from_sid}')"
Instance Method Summary collapse
- #build_query(binding_param_enabled = true) ⇒ Object
-
#initialize(table, schema, query_cond = {}) ⇒ DiffQueryGenerator
constructor
A new instance of DiffQueryGenerator.
Constructor Details
#initialize(table, schema, query_cond = {}) ⇒ DiffQueryGenerator
Returns a new instance of DiffQueryGenerator.
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# File 'lib/flydata/source_postgresql/query_based_sync/diff_query_generator.rb', line 20 def initialize(table, schema, query_cond = {}) @table = table @schema = schema @columns = query_cond[:columns] or raise ArgumentError, "columns is required" @from_sid = query_cond[:from_sid] @to_sid = query_cond[:to_sid] or raise ArgumentError, "to_sid is required" @pk_columns = query_cond[:pk_columns] or raise ArgumentError, "pk_columns is required" @last_pks = query_cond[:last_pks] @limit = query_cond[:limit] || DEFAULT_LIMIT end |
Instance Method Details
#build_query(binding_param_enabled = true) ⇒ Object
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# File 'lib/flydata/source_postgresql/query_based_sync/diff_query_generator.rb', line 32 def build_query(binding_param_enabled = true) from_sid_where_clause = if @from_sid FROM_SID_WHERE_CLAUSE % {from_sid: @from_sid} else nil end column_names, types = @columns.inject([[],[]]) do |arys, h| arys[0] << h[:column]; arys[1] << h[:type].gsub(/\(.+?\)/,''); arys end columns = column_list(column_names, types) query = FETCH_RECORDS_SQL % { columns: columns, table_name: fq_table_name(@table, @schema), where_clause: build_where_clause(@from_sid, @to_sid, @pk_columns, @last_pks, binding_param_enabled), order_by_clause: build_order_by_clause(@pk_columns), max_rows: @limit, } opts = { value_overriders: build_value_overriders(column_names, types) } if binding_param_enabled opts[:binding_params] = @last_pks end FlydataCore::Postgresql::PGQuery.new(query, opts) end |