Groovy's SQL support allows us to access ResultSetMetaData with a closure when we use the query methods rows() and eachRow(). We can pass a closure as the last argument of these methods. The closure parameter is the ResultSetMetaData object. The closure is only invoked once after the query is executed.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 | @Grapes([ @Grab(group='com.h2database', module='h2', version='1.3.160'), @GrabConfig(systemClassLoader = true)])import com.h2database.*import groovy.sql.*def db = Sql.newInstance('jdbc:h2:mem:', 'sa', '', 'org.h2.Driver')// Setup database.db.execute ''' create table if not exists languages( id int primary key, name varchar(20) not null )'''db.execute "insert into languages values(1, 'Groovy')"db.execute "insert into languages values(2, 'Java')"// Sample of meta closure:String query = 'select id as identifier, name as langName from languages'def rows = db.rows(query, { meta -> assert meta.tableName == 'languages' assert meta.columnCount == 2 assert meta.getColumnLabel(1) == 'IDENTIFIER' assert meta.getColumnName(1) == 'ID' assert meta.getColumnTypeName(1) == 'INTEGER' assert meta.getColumnLabel(2) == 'LANGNAME' assert meta.getColumnName(2) == 'NAME' assert meta.getColumnTypeName(2) == 'VARCHAR'}) |
