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Diffstat (limited to 'lib/impure/db_postgres.nim')
| -rw-r--r-- | lib/impure/db_postgres.nim | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/lib/impure/db_postgres.nim b/lib/impure/db_postgres.nim index 774cb1510..c88e660f4 100644 --- a/lib/impure/db_postgres.nim +++ b/lib/impure/db_postgres.nim @@ -16,6 +16,9 @@ type DbConn* = PPGconn ## encapsulates a database connection Row* = seq[string] ## a row of a dataset. NULL database values will be ## transformed always to the empty string. + InstantRow* = tuple[res: PPGresult, line: int32] ## a handle that can be + ## used to get a row's + ## column text on demand EDb* = object of IOError ## exception that is raised if a database error occurs SqlQuery* = distinct string ## an SQL query string @@ -159,6 +162,24 @@ iterator fastRows*(db: DbConn, stmtName: SqlPrepared, yield result pqClear(res) +iterator instantRows*(db: DbConn, query: SqlQuery, + args: varargs[string, `$`]): InstantRow + {.tags: [FReadDb].} = + ## same as fastRows but returns a handle that can be used to get column text + ## on demand using []. Returned handle is valid only within interator body. + var res = setupQuery(db, query, args) + for i in 0..pqNtuples(res)-1: + yield (res: res, line: i) + pqClear(res) + +proc `[]`*(row: InstantRow, col: int32): string {.inline.} = + ## returns text for given column of the row + $pqgetvalue(row.res, row.line, col) + +proc len*(row: InstantRow): int32 {.inline.} = + ## returns number of columns in the row + pqNfields(row.res) + proc getRow*(db: DbConn, query: SqlQuery, args: varargs[string, `$`]): Row {.tags: [FReadDB].} = ## retrieves a single row. If the query doesn't return any rows, this proc |