sql – 如何使用JDBC更新Oracle Clob

正常方式如下：

pStmt = conn.prepareStatement("SELECT DETAILS FROM PROGRAM_HISTORY WHERE id = 12");
    rset = pStmt.executeQuery();
    Clob detailsClob= rset.getClob(1);
    Writer writer = adapter.getCharacterOutputStream(detailsClob);
    writer.write("add more details"); 

    pStmt = conn.prepareStatement("UPDATE PROGRAM_HISTORY SET DETAILS = ? WHERE ID = 12");
    pStmt.setClob(1,detailsClob);
    pStmt.execute();

这有点复杂,是我不需要先阅读然后更新它的任何方式.就像更新varchar一样.

解决方法

不知道为什么你称之为“正常”的方式,但以下对我有用.

在更新之前,它不需要任何数据检索.

String value = "So long and thanks for all the fish";
StringReader reader = new StringReader(value);
pStmt = conn.prepareStatement("UPDATE PROGRAM_HISTORY SET DETAILS = ? WHERE ID = 12");
pStmt.setCharacterStream(1,reader,value.length();
pStmt.executeUpdate();