这是一些未知数据库载体的本地创建语句
String createStatement = "CREATE TABLE test_database.test_table " +
"AS " +
"( " +
"var1, " +
"var2 " +
") " +
"; "
);
我需要解析此字符串
test_database.test_table
我事先不知道该CREATE语句是什么SQL风格。如果我知道的话,我只会使用类似
String table = createStatement.split(" ")[2];
但是上述解决方案可能不适用于所有数据库。如果某些数据库在表名中允许空白怎么办?所以我必须使用Hibernate。
怎么样?
最佳答案
我认为Hibernate不能处理所有情况,尤其是在处理诸如Transact-SQL或CREATE GLOBAL TEMPORARY TABLE甚至CREATE TEMPORARY TABLESPACE之类的东西时,然后在使用AS,AS SELECT甚至PARALLEL COMPRESS AS SELECT之后,要考虑的表名。
但是,您也可以选择一种方法,该方法可以从提供的CREATE TABLE SQL字符串中检索表名,我相信它将涵盖大多数(如果不是全部)这些问题。下面是这样一种方法:
public String getTableNameFromCreate(final String sqlString) {
// Always rememeber...we're only trying to get the table
// name from the SQL String. We really don't care anything
// about the rest of the SQL string.
String tableName;
String wrkStrg = sqlString.replace("[", "").replace("]", "").trim();
// Is "CREATE TABLE" only
if (wrkStrg.startsWith("CREATE TABLE ")) {
wrkStrg = wrkStrg .substring(13).trim();
}
else if (wrkStrg.startsWith("CREATE GLOBAL TEMPORARY TABLE ")) {
wrkStrg = wrkStrg .substring(30).trim();
}
else if (wrkStrg.startsWith("CREATE TEMPORARY TABLESPACE ")) {
wrkStrg = wrkStrg .substring(28).trim();
}
// Is it Create Table ... AS, AS SELECT, PARALLEL COMPRESS AS,
// or PARALLEL COMPRESS AS SELECT?
if (wrkStrg.toUpperCase().contains(" PARALLEL COMPRESS ")) {
wrkStrg = wrkStrg.replace(" parallel compress ", " PARALLEL COMPRESS ");
tableName = wrkStrg.substring(0, wrkStrg.indexOf(" PARALLEL COMPRESS ")).trim();
}
else if (wrkStrg.toUpperCase().contains(" AS ")) {
wrkStrg = wrkStrg.replace(" as ", " AS ");
tableName = wrkStrg.substring(0, wrkStrg.indexOf(" AS ")).trim();
}
// Nope...none of that in the SQL String.
else {
tableName = wrkStrg.substring(0, wrkStrg.indexOf("(")).trim();
}
// return but remove quotes first if any...
return tableName.replace("\"","").replace("'", "");
}
如果像您的示例(test_database.test_table)一样将数据库名称附加到表名称,那么您当然需要进一步解析实际的表名称。
关于java - 如何使用Hibernate从CREATE语句解析表名?,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/41783875/