https://dev.mysql.com/doc/relnotes/mysql/8.0/en/news-8-0-1.html 

Incompatible Change: The my_bool type is no longer used in MySQL 

source code. Any third-party code that used this type to represent 

C boolean variables should use the bool or int C type instead.

Note

The change from my_bool to bool means that the mysql.h header file 

now requires a C++ or C99 compiler to compile.

(Bug #25597667)

--- src/sql/drivers/mysql/qsql_mysql.cpp.orig	2015-05-07 14:14:48 UTC

+++ src/sql/drivers/mysql/qsql_mysql.cpp

@@ -74,6 +74,14 @@ Q_DECLARE_METATYPE(MYSQL_STMT*)

 #  define Q_CLIENT_MULTI_STATEMENTS 0

 #endif

+// MYSQL 8.0.1 no longer uses the my_bool type:

+// https://dev.mysql.com/doc/relnotes/mysql/8.0/en/news-8-0-1.html

+#if MYSQL_VERSION_ID >= 80001

+typedef bool mysql_bool;

+#else

+typedef my_bool mysql_bool;

+#endif

+

 QT_BEGIN_NAMESPACE

 class QMYSQLDriverPrivate

@@ -194,7 +202,7 @@ class QMYSQLResultPrivate : public QObject (public)

               myField(0), type(QVariant::Invalid)

         {}

         char *outField;

-        my_bool nullIndicator;

+        mysql_bool nullIndicator;

         ulong bufLength;

         MYSQL_FIELD *myField;

         QVariant::Type type;

@@ -930,7 +938,7 @@ bool QMYSQLResult::exec()

     MYSQL_BIND* currBind;

     QVector<MYSQL_TIME *> timeVector;

     QVector<QByteArray> stringVector;

-    QVector<my_bool> nullVector;

+    QVector<mysql_bool> nullVector;

     const QVector<QVariant> values = boundValues();

@@ -951,7 +959,7 @@ bool QMYSQLResult::exec()

             currBind = &d->outBinds[i];

-            nullVector[i] = static_cast<my_bool>(val.isNull());

+            nullVector[i] = static_cast<mysql_bool>(val.isNull());

             currBind->is_null = &nullVector[i];

             currBind->length = 0;

             currBind->is_unsigned = 0;

@@ -1048,7 +1056,7 @@ bool QMYSQLResult::exec()

     d->rowsAffected = mysql_stmt_affected_rows(d->stmt);

     if (isSelect()) {

-        my_bool update_max_length = true;

+        mysql_bool update_max_length = true;

         r = mysql_stmt_bind_result(d->stmt, d->inBinds);

         if (r != 0) {

@@ -1245,7 +1253,7 @@ bool QMYSQLDriver::open(const QString& db,

     const QStringList opts(connOpts.split(QLatin1Char(';'), QString::SkipEmptyParts));

     QString unixSocket;

 #if MYSQL_VERSION_ID >= 50000

-    my_bool reconnect=false;

+    mysql_bool reconnect=false;

 #endif

     // extract the real options from the string

PORTREVISION=	1

https://dev.mysql.com/doc/relnotes/mysql/8.0/en/news-8-0-1.html

Incompatible Change: The my_bool type is no longer used in MySQL

source code. Any third-party code that used this type to represent

C boolean variables should use the bool or int C type instead.

Note

The change from my_bool to bool means that the mysql.h header file

now requires a C++ or C99 compiler to compile.

(Bug #25597667)

--- src/plugins/sqldrivers/mysql/qsql_mysql.cpp.orig	2018-04-29 07:25:09 UTC

+++ src/plugins/sqldrivers/mysql/qsql_mysql.cpp

@@ -74,6 +74,14 @@ Q_DECLARE_METATYPE(MYSQL_STMT*)

 #  define Q_CLIENT_MULTI_STATEMENTS 0

 #endif

+// MYSQL 8.0.1 no longer uses the my_bool type:

+// https://dev.mysql.com/doc/relnotes/mysql/8.0/en/news-8-0-1.html

+#if MYSQL_VERSION_ID >= 80001

+typedef bool mysql_bool;

+#else

+typedef my_bool mysql_bool;

+#endif

+

 QT_BEGIN_NAMESPACE

 class QMYSQLDriverPrivate : public QSqlDriverPrivate

@@ -232,7 +240,7 @@ class QMYSQLResultPrivate: public QSqlResultPrivate (p

               myField(0), type(QVariant::Invalid)

         {}

         char *outField;

-        my_bool nullIndicator;

+        mysql_bool nullIndicator;

         ulong bufLength;

         MYSQL_FIELD *myField;

         QVariant::Type type;

@@ -983,7 +991,7 @@ bool QMYSQLResult::exec()

     MYSQL_BIND* currBind;

     QVector<MYSQL_TIME *> timeVector;

     QVector<QByteArray> stringVector;

-    QVector<my_bool> nullVector;

+    QVector<mysql_bool> nullVector;

     const QVector<QVariant> values = boundValues();

@@ -1004,7 +1012,7 @@ bool QMYSQLResult::exec()

             currBind = &d->outBinds[i];

-            nullVector[i] = static_cast<my_bool>(val.isNull());

+            nullVector[i] = static_cast<mysql_bool>(val.isNull());

             currBind->is_null = &nullVector[i];

             currBind->length = 0;

             currBind->is_unsigned = 0;

@@ -1101,7 +1109,7 @@ bool QMYSQLResult::exec()

     d->rowsAffected = mysql_stmt_affected_rows(d->stmt);

     if (isSelect()) {

-        my_bool update_max_length = true;

+        mysql_bool update_max_length = true;

         r = mysql_stmt_bind_result(d->stmt, d->inBinds);

         if (r != 0) {

@@ -1312,7 +1320,7 @@ bool QMYSQLDriver::open(const QString& db,

     QString sslCAPath;

     QString sslCipher;

 #if MYSQL_VERSION_ID >= 50000

-    my_bool reconnect=false;

+    mysql_bool reconnect=false;

     uint connectTimeout = 0;

     uint readTimeout = 0;

     uint writeTimeout = 0;