/**
* Java version of table schema change. - Supports adding columns with default values (or null if
* none specified) - Supports dropping columns. - Supports widening of columns.
*
* <p>Note, this might fail in wierd ways if you ask it to do more than what the EE version can
* do. It's not really set up to test the negative cases.
*/
public static void migrateTable(VoltTable source, VoltTable dest) throws Exception {
Map<Integer, Integer> indexMap = new TreeMap<Integer, Integer>();
for (int i = 0; i < dest.getColumnCount(); i++) {
String destColName = dest.getColumnName(i);
for (int j = 0; j < source.getColumnCount(); j++) {
String srcColName = source.getColumnName(j);
if (srcColName.equals(destColName)) {
indexMap.put(i, j);
}
}
}
assert (dest.getRowCount() == 0);
source.resetRowPosition();
while (source.advanceRow()) {
Object[] row = new Object[dest.getColumnCount()];
// get the values from the source table or defaults
for (int i = 0; i < dest.getColumnCount(); i++) {
if (indexMap.containsKey(i)) {
int sourcePos = indexMap.get(i);
row[i] = source.get(sourcePos, source.getColumnType(sourcePos));
} else {
row[i] = dest.getColumnDefaultValue(i);
// handle no default specified
if (row[i] == TableShorthand.ColMeta.NO_DEFAULT_VALUE) {
if (dest.getColumnNullable(i)) {
row[i] = null;
} else {
throw new RuntimeException(
String.format(
"New column %s needs a default value in migration", dest.getColumnName(i)));
}
}
}
// make the values the core types of the target table
VoltType destColType = dest.getColumnType(i);
Class<?> descColClass = destColType.classFromType();
row[i] = ParameterConverter.tryToMakeCompatible(descColClass, row[i]);
// check the result type in an assert
assert (ParameterConverter.verifyParameterConversion(row[i], descColClass));
}
dest.addRow(row);
}
}
