readIf("COLUMN");
String columnName = readColumnIdentifier();
Column column = table.getColumn(columnName);
if (readIf("RENAME")) {
read("TO");
AlterTableRenameColumn command = new AlterTableRenameColumn(session);
command.setTable(table);
command.setColumn(column);
String newName = readColumnIdentifier();
command.setNewColumnName(newName);
return command;
} else if (readIf("DROP")) {
// PostgreSQL compatibility
if (readIf("DEFAULT")) {
AlterTableAlterColumn command = new AlterTableAlterColumn(session, table.getSchema());
command.setTable(table);
command.setOldColumn(column);
command.setType(CommandInterface.ALTER_TABLE_ALTER_COLUMN_DEFAULT);
command.setDefaultExpression(null);
return command;
}
read("NOT");
read("NULL");
AlterTableAlterColumn command = new AlterTableAlterColumn(session, table.getSchema());
command.setTable(table);
command.setOldColumn(column);
command.setType(CommandInterface.ALTER_TABLE_ALTER_COLUMN_NULL);
return command;
} else if (readIf("TYPE")) {
// PostgreSQL compatibility
return parseAlterTableAlterColumnType(table, columnName, column);
} else if (readIf("SET")) {
if (readIf("DATA")) {
// Derby compatibility
read("TYPE");
return parseAlterTableAlterColumnType(table, columnName, column);
}
AlterTableAlterColumn command = new AlterTableAlterColumn(session, table.getSchema());
command.setTable(table);
command.setOldColumn(column);
if (readIf("NULL")) {
command.setType(CommandInterface.ALTER_TABLE_ALTER_COLUMN_NULL);
return command;
} else if (readIf("NOT")) {
read("NULL");
command.setType(CommandInterface.ALTER_TABLE_ALTER_COLUMN_NOT_NULL);
return command;
} else if (readIf("DEFAULT")) {
Expression defaultExpression = readExpression();
command.setType(CommandInterface.ALTER_TABLE_ALTER_COLUMN_DEFAULT);
command.setDefaultExpression(defaultExpression);
return command;
}
} else if (readIf("RESTART")) {
readIf("WITH");
Expression start = readExpression();
AlterSequence command = new AlterSequence(session, table.getSchema());
command.setColumn(column);
command.setStartWith(start);
return command;
} else if (readIf("SELECTIVITY")) {
AlterTableAlterColumn command = new AlterTableAlterColumn(session, table.getSchema());
command.setTable(table);
command.setType(CommandInterface.ALTER_TABLE_ALTER_COLUMN_SELECTIVITY);
command.setOldColumn(column);
command.setSelectivity(readExpression());
return command;
} else {
return parseAlterTableAlterColumnType(table, columnName, column);
}
}