Class: ActiveRecord::ConnectionAdapters::IBM_DB2Adapter
- Inherits:
-
AbstractAdapter
- Object
- AbstractAdapter
- ActiveRecord::ConnectionAdapters::IBM_DB2Adapter
- Defined in:
- lib/connection_adapters/ibm_db2_adapter.rb
Instance Attribute Summary collapse
-
#iseries ⇒ Object
readonly
Returns the value of attribute iseries.
Instance Method Summary collapse
- #base_columns ⇒ Object
- #base_indexes ⇒ Object
- #base_initialize ⇒ Object
- #base_last_generated_id ⇒ Object
-
#columns(table_name, name = nil) ⇒ Object
Returns an array of Column objects for the table specified by
table_name
This method re-definition is valid only for iSeries. -
#constraints(table_name, name = nil) ⇒ Object
DrySQL queries the current schema’s System Catalog Views, which contain metadata only for those constraints that are defined in the current schema.
-
#indexes(table_name, name = nil) ⇒ Object
Returns an array of indexes for the given table, skipping the primary key.
-
#initialize(connection, logger, config) ⇒ IBM_DB2Adapter
constructor
A new instance of IBM_DB2Adapter.
-
#iseries_constraints(table_name, name = nil) ⇒ Object
This method retrieves constraint information from the iSeries information schema views, which DB2 generates automatically for a schema when it (the schema) is created.
Constructor Details
#initialize(connection, logger, config) ⇒ IBM_DB2Adapter
Returns a new instance of IBM_DB2Adapter.
184 185 186 187 188 189 190 |
# File 'lib/connection_adapters/ibm_db2_adapter.rb', line 184 def initialize(connection, logger, config) if (config[:platform] == "iseries") @iseries = true logger.info("DRYSQL >> iSeries platform detected") end base_initialize(connection, logger, config) end |
Instance Attribute Details
#iseries ⇒ Object (readonly)
Returns the value of attribute iseries.
181 182 183 |
# File 'lib/connection_adapters/ibm_db2_adapter.rb', line 181 def iseries @iseries end |
Instance Method Details
#base_columns ⇒ Object
193 |
# File 'lib/connection_adapters/ibm_db2_adapter.rb', line 193 alias :base_columns :columns |
#base_indexes ⇒ Object
242 |
# File 'lib/connection_adapters/ibm_db2_adapter.rb', line 242 alias :base_indexes :indexes |
#base_initialize ⇒ Object
183 |
# File 'lib/connection_adapters/ibm_db2_adapter.rb', line 183 alias :base_initialize :initialize |
#base_last_generated_id ⇒ Object
412 |
# File 'lib/connection_adapters/ibm_db2_adapter.rb', line 412 alias :base_last_generated_id :last_generated_id |
#columns(table_name, name = nil) ⇒ Object
Returns an array of Column objects for the table specified by table_name
This method re-definition is valid only for iSeries
196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 |
# File 'lib/connection_adapters/ibm_db2_adapter.rb', line 196 def columns(table_name, name = nil) # to_s required because it may be a symbol. table_name = table_name.to_s.upcase # Checks if a blank table name has been given. # If so it returns an empty array return [] if table_name.strip.empty? # +columns+ will contain the resulting array columns = [] if @iseries sql = "SELECT column_name, dftvalue as column_default, coltype as type, length, nulls, generated FROM SYSCOLUMNS WHERE TBNAME = '#{table_name}' AND DBNAME = '#{@schema.upcase}' ORDER BY colno" else sql = "SELECT colname as column_name, default as column_default, typename as type, length, nulls, generated FROM SYSCAT.COLUMNS WHERE TABNAME = '#{table_name}' AND TABSCHEMA = '#{@schema.upcase}' ORDER BY colno" end # Statement required to access all the columns information stmt = execute(sql, name) # Fetches all the columns and assigns them to col. # +col+ is an hash with keys/value pairs for a column while col = DB2::fetch_assoc(stmt) column_name = col["column_name"].downcase # Assigns the column default value. column_default_value = col["column_default"] # If there is no default value, it assigns NIL column_default_value = nil if (column_default_value && column_default_value.upcase == 'NULL') # Removes single quotes from the default value column_default_value.gsub!(/^'(.*)'$/, '\1') unless column_default_value.nil? # Assigns the column type column_type = col["type"].downcase # Assigns the field length (size) for the column column_length = col["length"] # The initializer of the class Column, requires the +column_length+ to be declared between brackets after # the datatype(e.g VARCHAR(50)) for :string and :text types. If it's a "for bit data" field it does a subsitution in place, if not # it appends the (column_length) string on the supported data types unless column_length.nil? || column_length == '' || column_type.sub!(/ \(\) for bit data/i,"(#{column_length}) FOR BIT DATA") || !column_type =~ /char|lob|graphic/i column_type << "(#{column_length})" end # col["NULLABLE"] is 1 if the field is nullable, 0 if not. column_nullable = col["nulls"] == 'Y' ? true : false generated = col["generated"] # Pushes into the array the *IBM_DB2Column* object, created by passing to the initializer # +column_name+, +default_value+, +column_type+ and +column_nullable+. columns << IBM_DB2Column.new(column_name, column_default_value, generated, column_type, column_nullable) end # Returns the columns array columns end |
#constraints(table_name, name = nil) ⇒ Object
DrySQL queries the current schema’s System Catalog Views, which contain metadata only for those constraints that are defined in the current schema.
If you have inter-schema referential constraints, and I’m not sure why you would or whether DB2 even supports this, DrySQL will not detect them and will raise an error.
297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 |
# File 'lib/connection_adapters/ibm_db2_adapter.rb', line 297 def constraints(table_name, name = nil)#:nodoc: constraints = [] if @iseries return iseries_constraints(table_name, name) else sql = "select CST.tabschema, CST.constname, CST.tabname, CST.type, COL.colname, \ REF.constname as foreign_constraint_name, REF.tabname as foreign_table_name, \ REF.refkeyname, REF.reftabname, REF.deleterule, REF.fk_colnames as foreign_columns, \ REF.pk_colnames as referenced_columns from \ ((select * from SYSCAT.TABCONST where tabname='#{table_name}') as CST \ inner join (select colname, constname from SYSCAT.KEYCOLUSE where tabname='#{table_name}') \ as COL on (CST.constname=COL.constname)) left outer join SYSCAT.REFERENCES REF on \ (CST.constname=REF.refkeyname or CST.constname=REF.constname)" end results = execute(sql, name) constraint_name_hash = {} # Note that column names in constraint objects are downcased in order to # be comparable with the column names produced by IBM_DB2Adapter.columns while row = DB2::fetch_assoc(results) constraint_name = row['constname'] foreign_constraint_name = row['foreign_constraint_name'] # Process constraints local to this table if !constraint_name_hash.has_key?(constraint_name) current_constraint = IBM_DB2Constraint.new(row['tabschema'], constraint_name, row['type'], row['tabname'], row['colname'], row['refkeyname'], row['reftabname'], row['referenced_columns'], row['deleterule']) constraints << current_constraint constraint_name_hash[constraint_name] = current_constraint # This key is a composite else current_constraint = constraint_name_hash[constraint_name] # Unique Keys are currently the only type of composite keys supported if current_constraint.component_of_unique_key? current_constraint.column_name.add(row['colname']) end end # Process constraints that reference this table's local constraints if !foreign_constraint_name.nil? && !constraint_name_hash.has_key?(foreign_constraint_name) current_foreign_constraint = IBM_DB2Constraint.new(row['tabschema'], foreign_constraint_name, IBM_DB2Constraint::FOREIGN_KEY_TYPE, row['foreign_table_name'], row['foreign_columns'], constraint_name, row['tabname'], row['colname'], row['deleterule']) constraints << current_foreign_constraint constraint_name_hash[foreign_constraint_name] = current_foreign_constraint # Composite FKs are currently not supported # else # constraint_name_hash[foreign_constraint_name].column_name.add(row['foreign_column_name']) end end constraints end |
#indexes(table_name, name = nil) ⇒ Object
Returns an array of indexes for the given table, skipping the primary key. The current implementation accesses SYSINDEXES and QSYS2.SYSKEYS. This method is valid only for iSeries
246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 |
# File 'lib/connection_adapters/ibm_db2_adapter.rb', line 246 def indexes(table_name, name = nil) if !@iseries then return base_indexes(table_name, name) end # to_s required because +table_name+ may be a symbol. table_name = table_name.to_s # Checks if a blank table name has been given. # If so it returns an empty array of columns. return [] if table_name.strip.empty? # +indexes+ will contain the resulting array indexes = [] # Query used to retrieve all the indexes from the given table sql = "select * from ((SELECT index_name, is_unique FROM SYSINDEXES WHERE table_name = '#{table_name.upcase}' AND table_schema = '#{@schema.upcase}') \ as IND inner join (select index_name, column_name from QSYS2.SYSKEYS where index_schema='#{@schema.upcase}') as KEYS on (IND.index_name=KEYS.index_name))" stmt = execute(sql, name) klass = instance_eval(ActiveRecord::Base.class_name(table_name)) primary_key = klass.primary_key index_hash = {} # Fetches all the records available while table_index = DB2::fetch_assoc(stmt) # Gets the lowercased index name index_name = table_index["index_name"].downcase # Is the index a primary key? unless index_name.upcase == primary_key.upcase # Is the index unique? index_unique = table_index["is_unique"] == 'U' if index_hash[index_name].nil? index_hash[index_name] = [index_unique, [column_name]] else index_hash[index_name][1] << column_name end end end # Creates IndexDefinition objects and adds them to the indexes array index_hash.keys.each do |key| current_index = index_hash[key] indexes << IndexDefinition.new(table_name, key, current_index[0], current_index[1]) end # Returns the indexes array return indexes # Ensures to free the resources associated with the statement ensure DB2::free_result(stmt) if stmt end |
#iseries_constraints(table_name, name = nil) ⇒ Object
This method retrieves constraint information from the iSeries information schema views, which DB2 generates automatically for a schema when it (the schema) is created.
Note that the old-style iSeries “libraries” that some people consider to by synonymous with “schemas” do not get the benefit of the information schema views (or journaling, for that matter). DrySQL will not play nicely with iSeries libraries unless you create the information schema views.
360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 |
# File 'lib/connection_adapters/ibm_db2_adapter.rb', line 360 def iseries_constraints(table_name, name = nil)#:nodoc: constraints = [] sql = "select CST.constraint_schema, CST.constraint_name, CST.table_name, CST.constraint_type, COL.column_name, \ REF.constraint_name as foreign_constraint_name, REF.unique_constraint_name as referenced_constraint_name, \ REF.delete_rule, COLREF.table_name as foreign_table_name, COLREF.column_name as foreign_column_name from \ ((select * from SYSCST where table_name='#{table_name}') as CST \ inner join (select column_name, constraint_name from SYSCSTCOL where table_name='#{table_name}') \ as COL on (CST.constraint_name=COL.constraint_name) left outer join SYSREFCST REF on \ (CST.constraint_name=REF.unique_constraint_name or CST.constraint_name=REF.constraint_name) \ left join SYSCSTCOL AS COLREF on (NOT COLREF.table_name='#{table_name}' AND \ (REF.unique_constraint_name=COLREF.constraint_name or REF.constraint_name=COLREF.constraint_name)))" results = execute(sql, name) constraint_name_hash = {} # Note that column names in constraint objects are downcased in order to # be comparable with the column names produced by IBM_DB2Adapter.columns while row = DB2::fetch_assoc(results) constraint_name = row['constraint_name'] foreign_constraint_name = row['foreign_constraint_name'] # Process constraints local to this table if !constraint_name_hash.has_key?(constraint_name) current_constraint = IBM_DB2Constraint.new(row['constraint_schema'], constraint_name, row['constraint_type'], row['table_name'], row['column_name'], row['referenced_constraint_name'], row['foreign_table_name'], row['foreign_column_name'], row['delete_rule']) constraints << current_constraint constraint_name_hash[constraint_name] = current_constraint # This key is a composite else current_constraint = constraint_name_hash[constraint_name] # Unique Keys are currently the only type of composite keys supported if current_constraint.component_of_unique_key? current_constraint.column_name.add(row['column_name']) end end # Process constraints that reference this table's local constraints if !foreign_constraint_name.nil? && !constraint_name_hash.has_key?(foreign_constraint_name) current_foreign_constraint = IBM_DB2Constraint.new(row['constraint_schema'], constraint_name, IBM_DB2Constraint::FOREIGN_KEY_TYPE, row['foreign_table_name'], row['foreign_column_name'], foreign_constraint_name, row['table_name'], row['column_name'], row['delete_rule']) constraints << current_foreign_constraint constraint_name_hash[foreign_constraint_name] = current_foreign_constraint # Composite FKs are currently not supported # else # constraint_name_hash[foreign_constraint_name].column_name.add(row['foreign_column_name']) end end constraints end |