diff options
Diffstat (limited to 'lib/impure/db_mysql.nim')
| -rwxr-xr-x | lib/impure/db_mysql.nim | 12 |
1 files changed, 7 insertions, 5 deletions
diff --git a/lib/impure/db_mysql.nim b/lib/impure/db_mysql.nim index 118ed39bb..41b3dc3bc 100755 --- a/lib/impure/db_mysql.nim +++ b/lib/impure/db_mysql.nim @@ -14,7 +14,8 @@ import strutils, mysql type TDbConn* = PMySQL ## encapsulates a database connection - TRow* = seq[string] ## a row of a dataset + TRow* = seq[string] ## a row of a dataset. NULL database values will be + ## transformed always to the empty string. EDb* = object of EIO ## exception that is raised if a database error occurs TSqlQuery* = distinct string ## an SQL query string @@ -111,7 +112,8 @@ iterator FastRows*(db: TDbConn, query: TSqlQuery, proc getRow*(db: TDbConn, query: TSqlQuery, args: varargs[string, `$`]): TRow {.tags: [FReadDB].} = - ## retrieves a single row. + ## retrieves a single row. If the query doesn't return any rows, this proc + ## will return a TRow with empty strings for each column. rawExec(db, query, args) var sqlres = mysql.UseResult(db) if sqlres != nil: @@ -150,9 +152,9 @@ iterator Rows*(db: TDbConn, query: TSqlQuery, proc GetValue*(db: TDbConn, query: TSqlQuery, args: varargs[string, `$`]): string {.tags: [FReadDB].} = - ## executes the query and returns the result dataset's the first column - ## of the first row. Returns "" if the dataset contains no rows. This uses - ## `FastRows`, so it inherits its fragile behaviour. + ## executes the query and returns the first column of the first row of the + ## result dataset. Returns "" if the dataset contains no rows or the database + ## value is NULL. result = "" for row in FastRows(db, query, args): result = row[0] |