给定HyperSQL中的一个表,其中包含一个UUID数组的列,构造INSERT
PreparedStatement
来填充此类字段的正确方法是什么?
SSCCE:
public class Example{
public static void main(String[] args) throws Exception{
// Create UUID array
UUID[] exmapleArray = new UUID[5];
for(int i = 0; i < exmapleArray.length; i++){
exmapleArray[i] = UUID.randomUUID();
}
// Load database class
Class.forName("org.hsqldb.jdbc.JDBCDriver");
// Connect to database
try(Connection databaseConnection = DriverManager.getConnection("jdbc:hsqldb:mem:foo")){
try(Statement createStatement = databaseConnection.createStatement()){
createStatement.executeUpdate("CREATE TABLE bar(test_field UUID ARRAY[10])");
}
try(PreparedStatement preparedStatement = databaseConnection.prepareStatement("INSERT INTO bar VALUES (?)")){
// None of the below examples work
// preparedStatement.setArray(1, databaseConnection.createArrayOf("UUID", exmapleArray));
// preparedStatement.setArray(1, databaseConnection.createArrayOf("VARCHAR", exmapleArray));
// preparedStatement.setArray(1, databaseConnection.createArrayOf("UUID", Arrays.stream(exmapleArray).map(UUID::toString).toArray()));
// preparedStatement.setArray(1, databaseConnection.createArrayOf("VARCHAR", Arrays.stream(exmapleArray).map(UUID::toString).toArray()));
// preparedStatement.setArray(1, new JDBCArrayBasic(exmapleArray, Type.BINARY_UUID));
// preparedStatement.setArray(1, new JDBCArrayBasic(Arrays.stream(exmapleArray).map(UUID::toString).toArray(), Type.BINARY_UUID));
preparedStatement.executeUpdate();
}
}
}
}
虽然可以用
UUID
填充数组来完成普通的PreparedStatement.setString()
的填充,但是似乎不起作用,取决于上面的语句选择,会产生几种不同的异常,最常见的是:Exception in thread "main" java.sql.SQLSyntaxErrorException: incompatible data type in conversion
at org.hsqldb.jdbc.JDBCUtil.sqlException(Unknown Source)
at org.hsqldb.jdbc.JDBCUtil.sqlException(Unknown Source)
at org.hsqldb.jdbc.JDBCConnection.createArrayOf(Unknown Source)
at Example.main(Example.java:31)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at com.intellij.rt.execution.application.AppMain.main(AppMain.java:147)
Caused by: org.hsqldb.HsqlException: incompatible data type in conversion
at org.hsqldb.error.Error.error(Unknown Source)
at org.hsqldb.error.Error.error(Unknown Source)
at org.hsqldb.types.CharacterType.convertToDefaultType(Unknown Source)
at org.hsqldb.types.CharacterType.convertJavaToSQL(Unknown Source)
... 7 more
被注释掉的后两个尝试使用特定于HSQLDB的类(特别是
JDBCArrayBasic
),该类类似地产生incompatible data type in conversion
。 最佳答案
我建议o使用循环填充您的PreparedStetement,例如,您必须使用insert an array:
INSERT INTO bar VALUES ARRAY[3.45, 23.64, 14.01]
因此,要填充数组,您必须使用如下循环:
String query = "INSERT INTO bar VALUES ARRAY[";
String del = "";
for (int i = 0; i < 10; i++) {
query += del+"?" ;
del = ",";
}
query += "]";
System.out.println(query);
您的查询直到现在看起来像这样:
INSERT INTO bar VALUES ARRAY[?,?,?,?,?,?,?,?,?,?]
您可以像这样完成:
PreparedStatement preparedStatement = connection.prepareStatement(query);
for (int i = 1; i <= 10; i++) {
preparedStatement.setString(i, "valu_"+i);
}
System.out.println("Query = " + preparedStatement.toString());
所以最后您的prepareStetement看起来像这样:
INSERT INTO bar VALUES ARRAY['valu_1','valu_2','valu_3','valu_4','valu_5','valu_6','valu_7','valu_8','valu_9','valu_10']
希望这可以给您一个想法。