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Spring JDBC Template Conditional Insert

开发者 https://www.devze.com 2023-01-23 18:53 出处:网络
I am trying to write a conditional batch insert based on Java Parameters, for example List<Object[]> params = new ArrayList();

I am trying to write a conditional batch insert based on Java Parameters, for example

List<Object[]> params = new ArrayList();
params.add(new Object[]{1, 2, 3});

getSimpleJdbcTemplate.batchUpdate(
"INSERT INTO SomeTable( colA, colB, colC)" +
 " VALUES(?开发者_开发百科, ?, ?)" +
 " WHERE EXISTS ( // some condition )", params);

This obviously does not work, and the closest example I have found involves selecting the INSERT values from tables, instead of the List arguments, which is what I need. How can I reference the Object[] parameters as part of the INSERT values?

Thank you.


I'd say that you should move this condition in a separate SELECT.


As your example, you should try following syntax and the SimpleJdbcOperations.update method:

getSimpleJdbcTemplate.update(
    " INSERT INTO SomeTable( colA, colB, colC)" +
    " SELECT srcA, srcB, srcC" +
    " FROM src_table" +
    " WHERE EXISTS ( // some condition )",
    params
);

Additionally, I've been using StringTemplate for generation of dynamic SQL. It's the best language I ever use.

for Example(As StringTemplate Syntax):

StringTemplate tmpl = new StringTemplate(
    " SELECT *" +
    " FROM some_table" +
    " WHERE 1 = 1" +
    "$search_age:{ AND age = ?}$" +
    "$search_name:{ AND name = ?}$"
);


/**
 * if param_age is not null, "AND age = ?" would be included in argumented sql,
 * same as param_name
 */
tmpl.setAttribute("age", param_age);
tmpl.setAttribute("name", param_name);
// :~)

String sqlTmpl = tmpl.toString(); // final SQL generated
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