The exclusion list was a subquery against `$GenConfig.DBName`.sys_tables,
so it named the schema by hand. Generating from a schema that is not the
one holding sys_tables made the whole query fail, and because the
subquery read the table directly it also counted soft-deleted entries:
deleting a generator entry never handed its table back.
Read the registrations through the model on this connection instead. An
empty list skips the clause - NOT IN (NULL) is unknown for every row,
which would leave a fresh install with nothing to generate from.
pkg.Assert panics when its condition is false, so pkg.Assert(true,
"目前只支持mysql数据库") is a no-op. On postgres or sqlserver the code
generator did not report that it needs MySQL: DBTables returned an empty
list with a nil error, and DBColumns ran its query on the zero-value
*gorm.DB left over from the branch that never assigned, which is a nil
dereference rather than a message.
Assert the driver up front instead of asserting a constant in an else,
which also removes the placeholder *gorm.DB the fall-through relied on.
DBColumns.GetPage had no guard at all and gets the same one.
pkg.Assert panics when its condition is false, so
Assert(TableName == "", "table name cannot be empty") rejected every
request that carried a table name and let the empty one through. The
model layer repeated the inversion with if TableName != "" { return
error }, so either one alone was enough to break the endpoint.
Flip both, and hoist the model guard out of the mysql branch so it
matches GetList ten lines below, which had it right all along.
zhangwenjian