Module: Sequel::SQLite::DatasetMethods
- Included in:
- Amalgalite::Dataset, DataObjects::SQLite::Dataset, JDBC::SQLite::Dataset, Dataset
- Defined in:
- lib/sequel/adapters/shared/sqlite.rb
Overview
Instance methods for datasets that connect to an SQLite database
Constant Summary collapse
- SELECT_CLAUSE_METHODS =
Dataset.clause_methods(:select, %w'distinct columns from join where group having compounds order limit')
- CONSTANT_MAP =
{:CURRENT_DATE=>"date(CURRENT_TIMESTAMP, 'localtime')".freeze, :CURRENT_TIMESTAMP=>"datetime(CURRENT_TIMESTAMP, 'localtime')".freeze, :CURRENT_TIME=>"time(CURRENT_TIMESTAMP, 'localtime')".freeze}
Instance Method Summary collapse
-
#complex_expression_sql(op, args) ⇒ Object
SQLite does not support pattern matching via regular expressions.
-
#constant_sql(constant) ⇒ Object
MSSQL doesn’t support the SQL standard CURRENT_DATE or CURRENT_TIME.
-
#delete ⇒ Object
SQLite performs a TRUNCATE style DELETE if no filter is specified.
-
#explain ⇒ Object
Return an array of strings specifying a query explanation for a SELECT of the current dataset.
-
#having(*cond, &block) ⇒ Object
HAVING requires GROUP BY on SQLite.
-
#quoted_identifier(c) ⇒ Object
SQLite uses the nonstandard ‘ (backtick) for quoting identifiers.
-
#supports_intersect_except_all? ⇒ Boolean
SQLite does not support INTERSECT ALL or EXCEPT ALL.
-
#supports_is_true? ⇒ Boolean
SQLite does not support IS TRUE.
-
#supports_multiple_column_in? ⇒ Boolean
SQLite does not support multiple columns for the IN/NOT IN operators.
-
#supports_timestamp_timezones? ⇒ Boolean
SQLite supports timezones in literal timestamps, since it stores them as text.
Instance Method Details
#complex_expression_sql(op, args) ⇒ Object
SQLite does not support pattern matching via regular expressions. SQLite is case insensitive (depending on pragma), so use LIKE for ILIKE.
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# File 'lib/sequel/adapters/shared/sqlite.rb', line 320 def complex_expression_sql(op, args) case op when :~, :'!~', :'~*', :'!~*' raise Error, "SQLite does not support pattern matching via regular expressions" when :LIKE, :'NOT LIKE', :ILIKE, :'NOT ILIKE' # SQLite is case insensitive for ASCII, and non case sensitive for other character sets "#{'NOT ' if [:'NOT LIKE', :'NOT ILIKE'].include?(op)}(#{literal(args.at(0))} LIKE #{literal(args.at(1))})" else super(op, args) end end |
#constant_sql(constant) ⇒ Object
MSSQL doesn’t support the SQL standard CURRENT_DATE or CURRENT_TIME
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# File 'lib/sequel/adapters/shared/sqlite.rb', line 333 def constant_sql(constant) CONSTANT_MAP[constant] || super end |
#delete ⇒ Object
SQLite performs a TRUNCATE style DELETE if no filter is specified. Since we want to always return the count of records, add a condition that is always true and then delete.
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# File 'lib/sequel/adapters/shared/sqlite.rb', line 340 def delete @opts[:where] ? super : filter(1=>1).delete end |
#explain ⇒ Object
Return an array of strings specifying a query explanation for a SELECT of the current dataset.
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# File 'lib/sequel/adapters/shared/sqlite.rb', line 346 def explain db.send(:metadata_dataset).clone(:sql=>"EXPLAIN #{select_sql}"). map{|x| "#{x[:addr]}|#{x[:opcode]}|#{(1..5).map{|i| x[:"p#{i}"]}.join('|')}|#{x[:comment]}"} end |
#having(*cond, &block) ⇒ Object
HAVING requires GROUP BY on SQLite
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# File 'lib/sequel/adapters/shared/sqlite.rb', line 352 def having(*cond, &block) raise(InvalidOperation, "Can only specify a HAVING clause on a grouped dataset") unless @opts[:group] super end |
#quoted_identifier(c) ⇒ Object
SQLite uses the nonstandard ‘ (backtick) for quoting identifiers.
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# File 'lib/sequel/adapters/shared/sqlite.rb', line 358 def quoted_identifier(c) "`#{c}`" end |
#supports_intersect_except_all? ⇒ Boolean
SQLite does not support INTERSECT ALL or EXCEPT ALL
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# File 'lib/sequel/adapters/shared/sqlite.rb', line 363 def supports_intersect_except_all? false end |
#supports_is_true? ⇒ Boolean
SQLite does not support IS TRUE
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# File 'lib/sequel/adapters/shared/sqlite.rb', line 368 def supports_is_true? false end |
#supports_multiple_column_in? ⇒ Boolean
SQLite does not support multiple columns for the IN/NOT IN operators
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# File 'lib/sequel/adapters/shared/sqlite.rb', line 373 def supports_multiple_column_in? false end |
#supports_timestamp_timezones? ⇒ Boolean
SQLite supports timezones in literal timestamps, since it stores them as text.
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# File 'lib/sequel/adapters/shared/sqlite.rb', line 379 def true end |