fix: EXPOSED-82 Inaccurate UShort column type mapping

Currently, when attempting to insert a UShort value outside of the range [0, 32767],
Exposed truncates the value by calling value.toShort() before sending it to the
DB, causing overflow. The value is stored successfully as a negative number because
all databases (except MySQL and MariaDB) don't support unsigned types natively,
which means Exposed is actually mapping to 2-byte `SMALLINT`, which accepts
the range [-32768, 32767].

Change the default mapping to the next higher-up integer data type INT (technically
a 4-byte storage type) and remove the truncation conversions so that an accurate
value is sent/received to/from the database. To ensure that the intended behavior
cannot be overriden using exec() directly, a check constraint is auto-applied to
the column when registered if the database is not MySQL/MariaDB.

Oracle INT is an alias for NUMBER(38), so this has been overriden to a reduced
type NUMBER(6).

exposed-core/src/main/kotlin/org/jetbrains/exposed/sql/ColumnType.kt

@@ -283,32 +283,33 @@ class ShortColumnType : ColumnType() {
 
 /**
  * Numeric column for storing unsigned 2-byte integers.
+ *
+ * **Note:** If the database being used is not MySQL or MariaDB, this column will represent the database's 4-byte
+ * integer type with a check constraint that ensures storage of only values between 0 and 65535 inclusive.
  */
 class UShortColumnType : ColumnType() {
     override fun sqlType(): String = currentDialect.dataTypeProvider.ushortType()
     override fun valueFromDB(value: Any): UShort {
         return when (value) {
             is UShort -> value
-            is Short -> value.takeIf { it >= 0 }?.toUShort()
-            is Number -> value.toInt().takeIf { it >= 0 && it <= UShort.MAX_VALUE.toInt() }?.toUShort()
+            is Short -> value.toUShort()
+            is Number -> value.toInt().toUShort()
             is String -> value.toUShort()
             else -> error("Unexpected value of type Short: $value of ${value::class.qualifiedName}")
-        } ?: error("Negative value but type is UShort: $value")
+        }
     }
 
     override fun setParameter(stmt: PreparedStatementApi, index: Int, value: Any?) {
-        val v = when {
-            value is UShort && currentDialect is MysqlDialect -> value.toInt()
-            value is UShort -> value.toShort()
+        val v = when (value) {
+            is UShort -> value.toInt()
             else -> value
         }
         super.setParameter(stmt, index, v)
     }
 
     override fun notNullValueToDB(value: Any): Any {
-        val v = when {
-            value is UShort && currentDialect is MysqlDialect -> value.toInt()
-            value is UShort -> value.toShort()
+        val v = when (value) {
+            is UShort -> value.toInt()
             else -> value
         }
         return super.notNullValueToDB(v)

exposed-core/src/main/kotlin/org/jetbrains/exposed/sql/Table.kt

@@ -360,6 +360,8 @@ open class Table(name: String = "") : ColumnSet(), DdlAware {
 
     private val checkConstraints = mutableListOf<Pair<String, Op<Boolean>>>()
 
+    private val generatedCheckPrefix = "chk_unsigned_"
+
     /**
      * Returns the table name in proper case.
      * Should be called within transaction or default [tableName] will be returned.
@@ -483,8 +485,14 @@ open class Table(name: String = "") : ColumnSet(), DdlAware {
     /** Creates a numeric column, with the specified [name], for storing 2-byte integers. */
     fun short(name: String): Column<Short> = registerColumn(name, ShortColumnType())
 
-    /** Creates a numeric column, with the specified [name], for storing 2-byte unsigned integers. */
-    fun ushort(name: String): Column<UShort> = registerColumn(name, UShortColumnType())
+    /** Creates a numeric column, with the specified [name], for storing 2-byte unsigned integers.
+     *
+     * **Note:** If the database being used is not MySQL or MariaDB, this column will use the database's 4-byte
+     * integer type with a check constraint that ensures storage of only values between 0 and 65535 inclusive.
+     */
+    fun ushort(name: String): Column<UShort> = registerColumn<UShort>(name, UShortColumnType()).apply {
+        check("$generatedCheckPrefix$name") { it.between(0u, UShort.MAX_VALUE) }
+    }
 
     /** Creates a numeric column, with the specified [name], for storing 4-byte integers. */
     fun integer(name: String): Column<Int> = registerColumn(name, IntegerColumnType())
@@ -1043,29 +1051,33 @@ open class Table(name: String = "") : ColumnSet(), DdlAware {
 
     /**
      * Creates a check constraint in this column.
-     * @param name The name to identify the constraint, optional. Must be **unique** (case-insensitive) to this table, otherwise, the constraint will
-     * not be created. All names are [trimmed][String.trim], blank names are ignored and the database engine decides the default name.
+     * @param name The name to identify the constraint, optional. Must be **unique** (case-insensitive) to this table,
+     * otherwise, the constraint will not be created. All names are [trimmed][String.trim], blank names are ignored and
+     * the database engine decides the default name.
      * @param op The expression against which the newly inserted values will be compared.
      */
     fun <T> Column<T>.check(name: String = "", op: SqlExpressionBuilder.(Column<T>) -> Op<Boolean>): Column<T> = apply {
         if (name.isEmpty() || table.checkConstraints.none { it.first.equals(name, true) }) {
             table.checkConstraints.add(name to SqlExpressionBuilder.op(this))
         } else {
-            exposedLogger.warn("A CHECK constraint with name '$name' was ignored because there is already one with that name")
+            exposedLogger
+                .warn("A CHECK constraint with name '$name' was ignored because there is already one with that name")
         }
     }
 
     /**
      * Creates a check constraint in this table.
-     * @param name The name to identify the constraint, optional. Must be **unique** (case-insensitive) to this table, otherwise, the constraint will
-     * not be created. All names are [trimmed][String.trim], blank names are ignored and the database engine decides the default name.
+     * @param name The name to identify the constraint, optional. Must be **unique** (case-insensitive) to this table,
+     * otherwise, the constraint will not be created. All names are [trimmed][String.trim], blank names are ignored and
+     * the database engine decides the default name.
      * @param op The expression against which the newly inserted values will be compared.
      */
     fun check(name: String = "", op: SqlExpressionBuilder.() -> Op<Boolean>) {
         if (name.isEmpty() || checkConstraints.none { it.first.equals(name, true) }) {
             checkConstraints.add(name to SqlExpressionBuilder.op())
         } else {
-            exposedLogger.warn("A CHECK constraint with name '$name' was ignored because there is already one with that name")
+            exposedLogger
+                .warn("A CHECK constraint with name '$name' was ignored because there is already one with that name")
         }
     }
 
@@ -1104,7 +1116,8 @@ open class Table(name: String = "") : ColumnSet(), DdlAware {
         return primaryKey?.let { primaryKey ->
             val tr = TransactionManager.current()
             val constraint = tr.db.identifierManager.cutIfNecessaryAndQuote(primaryKey.name)
-            return primaryKey.columns.joinToString(prefix = "CONSTRAINT $constraint PRIMARY KEY (", postfix = ")", transform = tr::identity)
+            return primaryKey.columns
+                .joinToString(prefix = "CONSTRAINT $constraint PRIMARY KEY (", postfix = ")", transform = tr::identity)
         }
     }
 
@@ -1140,10 +1153,17 @@ open class Table(name: String = "") : ColumnSet(), DdlAware {
                 }
 
                 if (checkConstraints.isNotEmpty()) {
-                    checkConstraints.mapIndexed { index, (name, op) ->
+                    val filteredChecks = if (currentDialect is MysqlDialect) {
+                        checkConstraints
+                            .filterNot { (name, _) -> name.startsWith(generatedCheckPrefix) }
+                            .ifEmpty { null }
+                    } else {
+                        checkConstraints
+                    }
+                    filteredChecks?.mapIndexed { index, (name, op) ->
                         val resolvedName = name.ifBlank { "check_${tableName}_$index" }
                         CheckConstraint.from(this@Table, resolvedName, op).checkPart
-                    }.joinTo(this, prefix = ", ")
+                    }?.joinTo(this, prefix = ", ")
                 }
 
                 append(")")
@@ -1159,7 +1179,8 @@ open class Table(name: String = "") : ColumnSet(), DdlAware {
         return createSequence + createTable + createConstraint
     }
 
-    override fun modifyStatement(): List<String> = throw UnsupportedOperationException("Use modify on columns and indices")
+    override fun modifyStatement(): List<String> =
+        throw UnsupportedOperationException("Use modify on columns and indices")
 
     override fun dropStatement(): List<String> {
         val dropTable = buildString {

exposed-core/src/main/kotlin/org/jetbrains/exposed/sql/vendors/Default.kt

@@ -26,8 +26,11 @@ abstract class DataTypeProvider {
     /** Numeric type for storing 2-byte integers. */
     open fun shortType(): String = "SMALLINT"
 
-    /** Numeric type for storing 2-byte unsigned integers. */
-    open fun ushortType(): String = "SMALLINT"
+    /** Numeric type for storing 2-byte unsigned integers.
+     *
+     * **Note:** If the database being used is not MySQL or MariaDB, this will represent the 4-byte integer type.
+     */
+    open fun ushortType(): String = "INT"
 
     /** Numeric type for storing 4-byte integers. */
     open fun integerType(): String = "INT"

exposed-core/src/main/kotlin/org/jetbrains/exposed/sql/vendors/OracleDialect.kt

@@ -7,6 +7,7 @@ import org.jetbrains.exposed.sql.transactions.TransactionManager
 internal object OracleDataTypeProvider : DataTypeProvider() {
     override fun byteType(): String = "SMALLINT"
     override fun ubyteType(): String = "SMALLINT"
+    override fun ushortType(): String = "NUMBER(6)"
     override fun integerType(): String = "NUMBER(12)"
     override fun integerAutoincType(): String = "NUMBER(12)"
     override fun uintegerType(): String = "NUMBER(13)"

exposed-tests/src/test/kotlin/org/jetbrains/exposed/sql/tests/shared/types/UnsignedColumnTypeTests.kt

@@ -6,24 +6,28 @@ import org.jetbrains.exposed.sql.insert
 import org.jetbrains.exposed.sql.selectAll
 import org.jetbrains.exposed.sql.tests.DatabaseTestsBase
 import org.jetbrains.exposed.sql.tests.TestDB
+import org.jetbrains.exposed.sql.tests.currentDialectTest
 import org.jetbrains.exposed.sql.tests.shared.assertEquals
+import org.jetbrains.exposed.sql.tests.shared.assertFailAndRollback
+import org.jetbrains.exposed.sql.tests.shared.assertTrue
+import org.jetbrains.exposed.sql.vendors.MysqlDialect
 import org.junit.Test
 
 class UnsignedColumnTypeTests : DatabaseTestsBase() {
-    object UByteTable : Table("uByteTable") {
-        val unsignedByte = ubyte("uByte")
+    object UByteTable : Table("ubyte_table") {
+        val unsignedByte = ubyte("ubyte")
     }
 
-    object UShortTable : Table("uShortTable") {
-        val unsignedShort = ushort("uShort")
+    object UShortTable : Table("ushort_table") {
+        val unsignedShort = ushort("ushort")
     }
 
-    object UIntTable : Table("uIntTable") {
-        val unsignedInt = uinteger("uInt")
+    object UIntTable : Table("uint_table") {
+        val unsignedInt = uinteger("uint")
     }
 
-    object ULongTable : Table("uLongTable") {
-        val unsignedLong = ulong("uLong")
+    object ULongTable : Table("ulong_table") {
+        val unsignedLong = ulong("ulong")
     }
 
     @Test
@@ -52,6 +56,34 @@ class UnsignedColumnTypeTests : DatabaseTestsBase() {
         }
     }
 
+    @Test
+    fun testUShortWithCheckConstraint() {
+        withTables(UShortTable) {
+            val ddlEnding = if (currentDialectTest is MysqlDialect) {
+                "(ushort SMALLINT UNSIGNED NOT NULL)"
+            } else {
+                "CHECK (ushort BETWEEN 0 and ${UShort.MAX_VALUE}))"
+            }
+            assertTrue(UShortTable.ddl.single().endsWith(ddlEnding, ignoreCase = true))
+
+            val number = 49151.toUShort()
+            assertTrue(number in Short.MAX_VALUE.toUShort()..UShort.MAX_VALUE)
+
+            UShortTable.insert { it[unsignedShort] = number }
+
+            val result = UShortTable.selectAll()
+            assertEquals(number, result.single()[UShortTable.unsignedShort])
+
+            // test that column itself blocks same out-of-range value that compiler blocks
+            assertFailAndRollback("Check constraint violation or out-of-range error (MySQL/MariaDB)") {
+                val tableName = UShortTable.nameInDatabaseCase()
+                val columnName = UShortTable.unsignedShort.nameInDatabaseCase()
+                val outOfRangeValue = UShort.MAX_VALUE + 1u
+                exec("""INSERT INTO $tableName ($columnName) VALUES ($outOfRangeValue)""")
+            }
+        }
+    }
+
     @Test
     fun testUIntColumnType() {
         withTables(UIntTable) {