• kdevel (16/16) Feb 23 2024 After the DIP 1036(e) discussions I am under the impression that
• Steven Schveighoffer (15/33) Feb 25 2024 This could be up to the db library to deal with. It would have to

kdevel <kdevel vogtner.de> writes:

After the DIP 1036(e) discussions I am under the impression that 
with the upcoming dmd release one shall be entitled to instead

     auto result = db.rows ("select id, a from b where id = ?", 
id);

write

     auto result = db.rows (i"select id, a from b where id = $id");

But what shall be written if the table from which the data are 
selected is variable, too? E.g.

     string t = "ta-ble";
     :
     auto result
        = db.rows ("select id, a from `" ~ t ~ "` where id = ?", 
id);

What if the escaping rules for table names and data are 
different? Can query authors benefit from string interpolation in 
this case?

Steven Schveighoffer <schveiguy gmail.com> writes:

On Friday, 23 February 2024 at 23:47:47 UTC, kdevel wrote:
 After the DIP 1036(e) discussions I am under the impression 
 that with the upcoming dmd release one shall be entitled to 
 instead

     auto result = db.rows ("select id, a from b where id = ?", 
 id);

 write

     auto result = db.rows (i"select id, a from b where id = 
 $id");

 But what shall be written if the table from which the data are 
 selected is variable, too? E.g.

     string t = "ta-ble";
     :
     auto result
        = db.rows ("select id, a from `" ~ t ~ "` where id = ?", 
 id);

 What if the escaping rules for table names and data are 
 different? Can query authors benefit from string interpolation 
 in this case?

This could be up to the db library to deal with. It would have to 
know the context of the interpolation to know whether to just 
straight-replace with the given string, or to use a prepared 
statement. My suggestion would be for the library to either have 
a specialized syntax, or a specialized type that it considers to 
be a part of the query that is runtime-decided-sql.

e.g.:

```d
RuntimeSql rsql(string data) { return RuntimeSql(data); }

...
auto result = db.rows(i"select id, a from $(t.rsql) where id = 
$(id)");
```

-Steve