mysql.bl3.mk suggested by Jaromir Dolecek (jdolecek@):

Default mysql package if there isn't any installed is mysql-4.1.7
(databases/mysql4-client)

You can choose a mysql package via MYSQL_VERSION_DEFAULT, it will
accept the following values:

MYSQL_VERSION_DEFAULT=41 # <- mysql-4.1.7
MYSQL_VERSION_DEFAULT=40 # <- mysql-4.0.21
MYSQL_VERSION_DEFAULT=30 # <- mysql-3.5.x

1 files changed, 81 insertions, 0 deletions

diff --git a/mk/mysql.buildlink3.mk b/mk/mysql.buildlink3.mk
new file mode 100644
index 00000000000..36507426532
--- /dev/null
+++ b/mk/mysql.buildlink3.mk
@@ -0,0 +1,81 @@
+# $NetBSD: mysql.buildlink3.mk,v 1.1 2004/10/28 11:28:27 xtraeme Exp $
+
+.if !defined(MYSQL_VERSION_MK)
+MYSQL_VERSION_MK=	# defined
+
+.include "../../mk/bsd.prefs.mk"
+
+MYSQL_VERSION_DEFAULT?=		41
+MYSQL_VERSIONS_ACCEPTED?=	41 40 30
+
+# transform the list into individual variables
+.for mv in ${MYSQL_VERSIONS_ACCEPTED}
+_MYSQL_VERSION_${mv}_OK=	yes
+.endfor
+
+# check what is installed
+.if exists(${LOCALBASE}/lib/mysql/libmysqlclient.so.14)
+_MYSQL_VERSION_41_INSTALLED=	yes
+.endif
+
+.if exists(${LOCALBASE}/lib/mysql/libmysqlclient.so.12)
+_MYSQL_VERSION_40_INSTALLED=	yes
+.endif
+
+.if exists(${LOCALBASE}/lib/mysql/libmysqlclient.so.10)
+_MYSQL_VERSION_30_INSTALLED=	yes
+.endif
+
+# if a version is explicitely required, take it
+.if defined(MYSQL_VERSION_REQD)
+_MYSQL_VERSION=	${MYSQL_VERSION_REQD}
+.endif
+# if the default is already installed, it is first choice
+.if !defined(_MYSQL_VERSION)
+.  if defined(_MYSQL_VERSION_${MYSQL_VERSION_DEFAULT}_OK)
+.    if defined(_MYSQL_VERSION_${MYSQL_VERSION_DEFAULT}_INSTALLED)
+_MYSQL_VERSION=	${MYSQL_VERSION_DEFAULT}
+.    endif
+.  endif
+.endif
+# prefer an already installed version, in order of "accepted"
+.if !defined(_MYSQL_VERSION)
+.  for mv in ${MYSQL_VERSIONS_ACCEPTED}
+.    if defined(_MYSQL_VERSION_${mv}_INSTALLED)
+_MYSQL_VERSION?=	${mv}
+.    else
+# keep information as last resort - see below
+_MYSQL_VERSION_FIRSTACCEPTED?=	${mv}
+.    endif
+.  endfor
+.endif
+# if the default is OK for the addon pkg, take this
+.if !defined(_MYSQL_VERSION)
+.  if defined(_MYSQL_VERSION_${MYSQL_VERSION_DEFAULT}_OK)
+_MYSQL_VERSION=	${MYSQL_VERSION_DEFAULT}
+.  endif
+.endif
+# take the first one accepted by the package
+.if !defined(_MYSQL_VERSION)
+_MYSQL_VERSION=	${_MYSQL_VERSION_FIRSTACCEPTED}
+.endif
+
+#
+# set variables for the version we decided to use:
+#
+.if ${_MYSQL_VERSION} == "41"
+MYSQL_PKGSRCDIR=	../../databases/mysql4-client
+.elif ${_MYSQL_VERSION} == "40"
+MYSQL_PKGSRCDIR=	../../databases/mysql-client
+.elif ${_MYSQL_VERSION} == "30"
+MYSQL_PKGSRCDIR=	../../databases/mysql3-client
+.else
+# force an error
+PKG_SKIP_REASON+=	"${_MYSQL_VERSION} is not a valid mysql package."
+.endif
+
+.if (defined(USE_BUILDLINK3) && empty(USE_BUILDLINK3:M[nN][oO]))
+.  include "${MYSQL_PKGSRCDIR}/buildlink3.mk"
+.endif
+
+.endif	# MYSQL_VERSION_MK