[英]How to create MySQL Procedures from java code when software runs for first time (Setting up database procedures))
我想在我的应用程序首次在新设备上运行时设置数据库。 为此,我必须创建必要的表,存储过程等。我在应用程序的初始启动时成功创建了表。 但是我无法对过程实施相同的操作。
我尝试在第一次启动应用程序时执行存储过程查询。 尽管创建过程的MySQL代码是正确的,但是Java给出了错误提示
java.sql.BatchUpdateException:您的SQL语法有错误; 检查与您的MySQL服务器版本相对应的手册,以在第1行的'DELIMITER // CREATE PROCEDURE update_registered_fields(IN _field VARCHAR(200))'附近使用正确的语法 。
我没有在这里显示与数据库的连接,因为它工作正常。 我已经使用了procedures.xml文件来获取代码查询。
数据库处理程序
private static void inflateProcedure() throws SQLException, FileNotFoundException, ParserConfigurationException, SAXException, IOException{
Set<String> set = new HashSet<>();
List<String> procedureData = new ArrayList<>();
String query = "SHOW PROCEDURE STATUS WHERE Db = '"+Preferences.getPreferences().getDatabaseName()+"';";
System.out.println(query);
stmnt = con.createStatement();
ResultSet rs = stmnt.executeQuery(query);
while(rs.next()){
set.add(rs.getString("NAME").toLowerCase());
}
System.out.println("Already Loaded Procedures "+set);
DocumentBuilderFactory dbFactory = DocumentBuilderFactory.newInstance();
DocumentBuilder dBuilder = dbFactory.newDocumentBuilder();
Document doc = dBuilder.parse(new FileInputStream(Preferences.getPreferences().getLocation()+"procedures.xml"));
NodeList nList = doc.getElementsByTagName("table-entry");
for (int i = 0; i < nList.getLength(); i++) {
Node nNode = nList.item(i);
Element entry = (Element) nNode;
String procedureName = entry.getAttribute("name");
String params = entry.getAttribute("params");
String procedureQuery = entry.getAttribute("data");
if (!set.contains(procedureName.toLowerCase())) {
procedureData.add(String.format("DELIMITER // CREATE PROCEDURE %s %s \n"
+ "BEGIN;\n"
+ " %s \n"
+ "END //\n DELIMITER ", procedureName, params, procedureQuery));
}
}
if (procedureData.isEmpty()) {
System.out.println("Procedures are already loaded");
}
else {
System.out.println("Inflating new Procedures.");
createProcedures(procedureData);
}
}
private static void createProcedures(List<String> procedureData) throws SQLException{
Statement statement = con.createStatement();
for (String command : procedureData) {
System.out.println(command);
statement.addBatch(command);
}
statement.executeBatch();
statement.close();
}
Procedures.xml
<procedures>
<table-entry name="update_registered_fields" params="(IN _field VARCHAR(200))" data="DECLARE _value INT DEFAULT 0;
SET _value := (SELECT `user_register_feilds`.`last_used` FROM `user_register_feilds` WHERE `user_register_feilds`.`name` = _field);
UPDATE `user_register_feilds` SET `user_register_feilds`.`last_used` = _value+1 WHERE `user_register_feilds`.`name` = _field;"/>
<table-entry name="sort_fields" params="(IN _value INT(50))" data="SELECT * FROM user_enquiry ORDER BY last_used DESC, id ASC LIMIT _value;"/>
我要执行此查询。 我什至尝试过allowMultiQueries
。 我还想知道,这是我们首次启动应用程序时填充数据库的正确方法。
您似乎在sql查询中使用了定界符,试图在JDBC中运行,这从错误消息中可以明显看出: java.sql.BatchUpdateException: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'DELIMITER // CREATE PROCEDURE update_registered_fields (IN _field VARCHAR(200))' at line 1
java.sql.BatchUpdateException: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'DELIMITER // CREATE PROCEDURE update_registered_fields (IN _field VARCHAR(200))' at line 1
。
尝试删除定界符。 在原始sql中使用定界符。 JDBC不需要定界符。
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