Allow NamedParameterJdbcTemplate to optionally include parameters in comments of SQL

[benelog]

NamedParameterJdbcTemplate skips parameters in comments by the logic in NamedParameterUtils.parseSqlStatement(String sql)

...
			int skipToPosition = i;
			while (i < statement.length) {
				skipToPosition = skipCommentsAndQuotes(statement, i);
				if (i == skipToPosition) {
					break;
				}
				else {
					i = skipToPosition;
				}
			}

...

I use NamedParameterJdbcTemplate to run SQLs on our own DBMS engine in the company.
I have special cases to use parameters in comment, for example, "/*@ queryCkey(:cafeId) */ SELECT ... ",

If it is allowed in NamedParameterJdbcTemplate, it will be very helpful for our system.
( For your information, MyBatis allows parameters in comments of SQL)

I'd like you to consider adding an optional flag to support this.

var template = new NamedParameterJdbcTemplate(dataSource);
template.setAllowParametersInComments(true);

[pashazadeh]

Setting this kind of parameters is not supported by PreparedStatements, because they change the execution plan of the query. Cause major databases support which support prepared-statements just parse the query once, so they don't accept placeholders for what changes the execution plan.

[benelog]

@pashazadeh
I understand your concerns. It is reasonable default to disable parameters in comments.

However, if it is customizable, it will be very helpful for developers who use a special DBMS like us.
If the JDBC driver allows it, I think it's unnatural to prevent it in the Spring framework. So, MyBatis also seems to allow this.

Since Spring framework is traditionally highly customizable, I expect that.

[junoyoon]

Or.. I think it can be solved by making skipCommentsAndQuotes protected and non-static so that it can be extended in the sub-class of NamedParemterJdbcTemplate .

[snicoll]

The problem is that we delegate everything to NamedParameterUtils that is static at the moment. I think we'd probably need to make it non static and offer some way to customize it.

With the interesting feedback of @pashazadeh, I am wondering though if it would be a good idea to support it.

@benelog can't you use simple ? for those advanced use cases, rather than named parameters?

[benelog]

@snicoll
Unfortunately, all queries in our system require parameters within SQL hints.
We use our company's own DBMS system, and this DBMS requires that the shard key be included in the hint.
The cost of giving up the NamedParameterJdbcTemplate is high in this case.

We are currently working around this issue by creating a class that inherited the NamedParameterJdbcTemplate.
It is also possible to maintain this workaround.
I raised this issue because there is an internal opinion that it would be beneficial if NamedParameterJdbcTemplate could directly support what is already allowed in MyBatis.

If we are the only ones who want this feature, it would be okay for you to consider implementing it when other users request it too.

[snicoll]

We are currently working around this issue by creating a class that inherited the NamedParameterJdbcTemplate.

Can you share your workaround?