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Query Debugging
Overview
You can see the SQL generated from a Query without having to connect to the database.
dryRun
Calling the dryRun function on a Query allows you
to see the SQL and the arguments bound to the query:
val query: Query<List<Address>> = QueryDsl.from(a).where { a.addressId eq 1 }
val result: DryRunResult = query.dryRun()
println(result)
The output result of the above code is as follows (line breaks are inserted for readability):
DryRunResult(
sql=select t0_.ADDRESS_ID, t0_.STREET, t0_.VERSION from ADDRESS as t0_ where t0_.ADDRESS_ID = ?,
sqlWithArgs=select t0_.ADDRESS_ID, t0_.STREET, t0_.VERSION from ADDRESS as t0_ where t0_.ADDRESS_ID = 1,
args=[Value(any=1, klass=class kotlin.Int)],
throwable=null,
description=This data was generated using DryRunDatabaseConfig. To get more correct information, specify the actual DatabaseConfig instance.
)
The meaning of the properties of the DryRunResult class is as follows:
- sql
- The SQL generated from the query.
Bind variables are represented by
?. If an exception occurs, the exception message is expressed instead of SQL. - sqlWithArgs
- The SQL with arguments generated from the query. Bind variables are replaced by string representations of the arguments. If an exception occurs, the exception message is expressed instead of SQL.
- args
- Argument value/type pairs.
- throwable
- Exception thrown during SQL generation. If no exception was thrown,
null. - description
- Description for the instance of
DryRunResult.
Using Dialect
The dryRun function with no arguments returns a result without considering
the Dialect of the destination database.
If you want to get the result considering Dialect, pass a DatabaseConfig instance.
val database: JdbcDatabase = ...
val query: Query<List<Address>> = QueryDsl.from(a).where { a.addressId eq 1 }
val result: DryRunResult = query.dryRun(database.config)
println(result)
Or call the dryRun function of the Database instance.
val database: JdbcDatabase = ...
val query: Query<List<Address>> = QueryDsl.from(a).where { a.addressId eq 1 }
val result: DryRunResult = database.dryRun(query)
println(result)
Debugging during query construction
Combined with the also function, you can check query information during the construction process.
val query: Query<List<Address>> = QueryDsl.from(a)
.also {
println("1:" + it.dryRun().sql)
}.where {
a.addressId eq 1
}.also {
println("2:" + it.dryRun().sql)
}.orderBy(a.addressId)
.also {
println("3:" + it.dryRun().sql)
}
The results of executing the above code are as follows:
1:select t0_.ADDRESS_ID, t0_.STREET, t0_.VERSION from ADDRESS as t0_
2:select t0_.ADDRESS_ID, t0_.STREET, t0_.VERSION from ADDRESS as t0_ where t0_.ADDRESS_ID = ?
3:select t0_.ADDRESS_ID, t0_.STREET, t0_.VERSION from ADDRESS as t0_ where t0_.ADDRESS_ID = ? order by t0_.ADDRESS_ID asc