2
根據HSQL documentation只有SQL過程需要CALL語法。我正在寫一個SQL函數，但我不能從它SELECT。我只能CALL它。任何人都可以看到我錯過的東西？這裏是我的代碼爲什麼我可以用SELECT調用HSQL函數，但不能調用？
public static void main(String[] args) throws Exception {
Class<?> driverClass = Class.forName("org.hsqldb.jdbcDriver");
JDBCDriver driver = (JDBCDriver) driverClass.newInstance();
Properties props = new Properties();
props.setProperty("user", "sa");
props.setProperty("password", "");
Connection c = driver.connect("jdbc:hsqldb:mem:aname", props);
execute(c, "CREATE TABLE T (i INT)");
execute(c, "INSERT INTO T VALUES (1)");
execute(c, "CREATE FUNCTION f() RETURNS TABLE (i INT) READS SQL DATA " +
" RETURN TABLE (SELECT * FROM T)");
System.out.println("Call returns the ResultSet:");
execute(c, "{ CALL f() }");
try {
execute(c, "SELECT * FROM f()");
} catch (Exception e) {
System.out.println("Select throws the exception:");
System.out.println(e);
}
}
private static void execute(Connection c, String sql) throws SQLException {
Statement s = c.createStatement();
try {
s.execute(sql);
ResultSet rs = s.getResultSet();
if (rs != null) {
printResultSet(rs);
}
} finally {
s.close();
}
}
private static void printResultSet(ResultSet rs) throws SQLException {
try {
while (rs.next()) {
int columnCount = rs.getMetaData().getColumnCount();
for (int i = 1; i <= columnCount; i++) {
System.out.println(rs.getObject(i));
}
}
} finally {
rs.close();
}
}
我得到的輸出：
Call returns the ResultSet:
1
Select throws the exception:
java.sql.SQLSyntaxErrorException: user lacks privilege or object not found: F