tcl var substitution in sqlite3 eval - sqlite

Question

I have a file filled with sqlite statements I'd like to parse. I've done so previously using the C-interface but now I have trouble with the Tcl interface.
sqlite3 cspdb ":memory:"
set s [read [set f [open csp_sql.txt]]]
set ms [string map {"\n" "\0"} $s]
puts $ms
cspdb eval {$ms}
The error I get is:
"near "$ms": syntax error while executing cspdb eval {$ms}"
It works fine when I paste the output from puts $ms directly into the eval brackets. I also tried "{$ms}" and just plain $ms but the result is the same; syntax error.
I might chose another solution for the problem all together but it really bugs my why it does not work...
Here is what the file looks like:
BEGIN TRANSACTION;
CREATE TABLE Symbol (
Label TEXT PRIMARY KEY,
Type TEXT DEFAULT('no_type')
);
CREATE TABLE Process (
Name INTEGER PRIMARY KEY,
Type TEXT DEFAULT('no_type')
);
CREATE TABLE Named_Process (
Label TEXT UNIQUE,
Definition INTEGER UNIQUE,
FOREIGN KEY(Label) REFERENCES Symbol (Label),
FOREIGN KEY(Definition) REFERENCES Definition(Name)
);
CREATE TABLE Definition (
Name INTEGER UNIQUE,
Definition INTEGER,
FOREIGN KEY(Name) REFERENCES Process(Name),
FOREIGN KEY(Definition) REFERENCES Process(Name)
);
CREATE TABLE Reference (
Name INTEGER UNIQUE,
Reference TEXT,
FOREIGN KEY(Name) REFERENCES Process(Name),
FOREIGN KEY(Reference) REFERENCES Definition(Name)
);
CREATE TABLE Event (
Label TEXT PRIMARY KEY,
Type TEXT DEFAULT('no_type')
);
CREATE TABLE Environment (
Label TEXT UNIQUE,
FOREIGN KEY (Label) REFERENCES Event (Label)
);
CREATE TABLE Prefix (
Name INTEGER UNIQUE,
P INTEGER,
Event TEXT,
FOREIGN KEY (Name) REFERENCES Process (Name),
FOREIGN KEY (P) REFERENCES Process (Name),
FOREIGN KEY (Event) REFERENCES Event (Label)
);
CREATE TABLE Choice (
Name INTEGER UNIQUE,
P INTEGER,
Q INTEGER,
FOREIGN KEY(Name) REFERENCES Process(Name),
FOREIGN KEY(P) REFERENCES Process(Name),
FOREIGN KEY(Q) REFERENCES Process(Name)
);
/* Language defined processes */
/* SKIP */
INSERT INTO Symbol(Label,Type) VALUES('SKIP','named_process');
INSERT INTO Named_Process(Label) VALUES('SKIP');
INSERT INTO Process(type) VALUES('definition');
UPDATE Named_Process SET Definition=last_insert_rowid() WHERE Label='SKIP';
INSERT INTO Definition(Name,Definition) VALUES(last_insert_rowid(),last_insert_rowid());
END TRANSACTION;
(Not so sure removing newlines is necessary...)

Answer 1

If the string that you've read from the file is SQL, you should be able to do this:
sqlite3 cspdb ":memory:"
set f [open "csp_sql.txt"]
set sql [read $f]
close $f
cspdb eval $sql
By comparison, the literal string $ms is not a valid SQL statement or query, nor is it syntactically legal to surround a SQL statement with braces (which is what "{$ms}" ended up doing; the outer "…" makes the inside just a bunch of characters).
I don't know why you are translating newlines into NULs, but that's really unlikely to be a good idea. Bulk import of data (possibly with NULs in it) should be done in a different way.

Answer 2

The eval subcommand created by Sqlite does limited variable substitution, but only in places where a string value is expected.
Try
cspdb eval $ms
to let the Tcl interpreter substitute the SQL statements before sending them to eval.

Answer 3

turns out the newline-to-null was the culprit making substitution fail. final working code:
sqlite3 cspdb ":memory:"
cspdb eval [read [set f [open csp_sql.txt]]]
the reason newline-to-null turned up at all was when trying to debug making the string match my original working C-code which used multiline string literals in which newlines diappeared. Except, "\0" is not a "disappearing" character...