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Add database/sql to overview of scanning

pull/2266/head
Jack Christensen 2025-02-22 08:42:26 -06:00
parent 14bda65a0c
commit 6bf1b0b1b9
1 changed files with 6 additions and 0 deletions
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pgtype/doc.go
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@ -164,6 +164,12 @@ plan for scanning into the Go value. A Codec will support scanning into one or m
are interfaces rather than explicit types. For example, PointCodec can use any Go type that implements the PointScanner
and PointValuer interfaces.
If a Go value is not supported directly by a Codec then Map will try see if it is a sql.Scanner. If is then that
interface will be used to scan the value. Most sql.Scanners require the input to be in the text format (e.g. UUIDs and
numeric). However, pgx will typically have received the value in the binary format. In this case the binary value will be
parsed, reencoded as text, and then passed to the sql.Scanner. This may incur additional overhead for query results with
a large number of affected values.
If a Go value is not supported directly by a Codec then Map will try wrapping it with additional logic and try again.
For example, Int8Codec does not support scanning into a renamed type (e.g. type myInt64 int64). But Map will detect that
myInt64 is a renamed type and create a plan that converts the value to the underlying int64 type and then passes that to