fixes sqlite3_column_count() return check

sqlite3_column_count() may return 0 for SQL statements that do not return rows
from the database.  This should not be treated as an error.

See:  https://sqlite.org/c3ref/column_count.html
This commit is contained in:
jazzyb
2015-04-16 22:29:50 -04:00
parent 58e5e6ed55
commit 0a073b18e9
2 changed files with 16 additions and 4 deletions

View File

@@ -546,8 +546,10 @@ do_column_names(ErlNifEnv *env, sqlite3_stmt *stmt)
ERL_NIF_TERM column_names;
size = sqlite3_column_count(stmt);
if(size <= 0)
return make_error_tuple(env, "no_columns");
if(size == 0)
return enif_make_tuple(env, 0);
else if(size < 0)
return make_error_tuple(env, "invalid_column_count");
array = (ERL_NIF_TERM *) malloc(sizeof(ERL_NIF_TERM) * size);
if(!array)
@@ -577,8 +579,10 @@ do_column_types(ErlNifEnv *env, sqlite3_stmt *stmt)
ERL_NIF_TERM column_types;
size = sqlite3_column_count(stmt);
if(size <= 0)
return make_error_tuple(env, "no_columns");
if(size == 0)
return enif_make_tuple(env, 0);
else if(size < 0)
return make_error_tuple(env, "invalid_column_count");
array = (ERL_NIF_TERM *) malloc(sizeof(ERL_NIF_TERM) * size);
if(!array)

View File

@@ -178,6 +178,10 @@ column_names_test() ->
{row, {Date}} = esqlite3:step(Stmt4),
true = is_binary(Date),
%% Some statements have no column names
{ok, Stmt5} = esqlite3:prepare("create table dummy(a, b, c);", Db),
{} = esqlite3:column_names(Stmt5),
ok.
column_types_test() ->
@@ -198,6 +202,10 @@ column_types_test() ->
'$done' = esqlite3:step(Stmt),
{'varchar(10)', int} = esqlite3:column_types(Stmt),
%% Some statements have no column types
{ok, Stmt2} = esqlite3:prepare("create table dummy(a, b, c);", Db),
{} = esqlite3:column_types(Stmt2),
ok.
nil_column_types_test() ->