query_scalar

query_scalar :: (
    db: $D,
    $sql: string,
    args: ..Any,
    plan := Plan.AUTO,
    json := Json_Options.{},
    $call := #caller_code
) -> (type_of(Scalar(#run scalar_type(sql, call, 1)).value), Pg_Error)

The first column of the only row.

Parameters

db: $D

a *Connection or a *Pool.

$sql: string

the statement, written at the call as a string: % marks each argument, %% is a literal %.

args: ..Any

one value per %, in order.

plan := Plan.AUTO

.AUTO runs it as a cached named statement; .CUSTOM plans it again on every run.

json := Json_Options.{}

decoding options for json columns in this query; they apply over the connection's and the column's.

$call := #caller_code

the code of the call, which lets the query text be checked while compiling. Leave the default.

Returns

type_of(Scalar(#run scalar_type(sql, call, 1)).value)

Pg_Error