Revert "Introduce Mode enum for H2 compatibility modes with deprecation of old constants"

This reverts commit d4aab31.

Author: zaleslaw

dataframe-jdbc/src/main/kotlin/org/jetbrains/kotlinx/dataframe/io/db/H2.kt

@@ -18,7 +18,6 @@ public open class H2(public val dialect: DbType = MySql) : DbType("h2") {
         require(dialect::class != H2::class) { "H2 database could not be specified with H2 dialect!" }
     }
 
-
     /**
      * It contains constants related to different database modes.
      *
@@ -30,36 +29,16 @@ public open class H2(public val dialect: DbType = MySql) : DbType("h2") {
      * @see [createH2Instance]
      */
     public companion object {
-        /**
-         * Represents the compatibility modes supported by an H2 database.
-         *
-         * @property value The string value used in H2 JDBC URL and settings.
-         */
-        public enum class Mode(public val value: String) {
-            MySql("MySQL"),
-            PostgreSql("PostgreSQL"),
-            MsSqlServer("MSSQLServer"),
-            MariaDb("MariaDB");
-
-            public companion object {
-                /**
-                 * Finds a Mode by its string value (case-insensitive).
-                 *
-                 * @param value The string value to search for.
-                 * @return The matching Mode, or null if not found.
-                 */
-                public fun fromValue(value: String): Mode? =
-                    entries.find { it.value.equals(value, ignoreCase = true) }
-            }
-        }
-
-        @Deprecated("Use Mode.MySql.value instead", ReplaceWith("Mode.MySql.value"))
+        /** It represents the mode value "MySQL" for the H2 database. */
         public const val MODE_MYSQL: String = "MySQL"
-        @Deprecated("Use Mode.PostgreSql.value instead", ReplaceWith("Mode.PostgreSql.value"))
+
+        /** It represents the mode value "PostgreSQL" for the H2 database. */
         public const val MODE_POSTGRESQL: String = "PostgreSQL"
-        @Deprecated("Use Mode.MsSqlServer.value instead", ReplaceWith("Mode.MsSqlServer.value"))
+
+        /** It represents the mode value "MSSQLServer" for the H2 database. */
         public const val MODE_MSSQLSERVER: String = "MSSQLServer"
-        @Deprecated("Use Mode.MariaDb.value instead", ReplaceWith("Mode.MariaDb.value"))
+
+        /** It represents the mode value "MariaDB" for the H2 database. */
         public const val MODE_MARIADB: String = "MariaDB"
     }
 

dataframe-jdbc/src/test/kotlin/org/jetbrains/kotlinx/dataframe/io/h2/h2Test.kt

@@ -974,31 +974,6 @@ class JdbcTest {
         exception.message shouldBe "H2 database could not be specified with H2 dialect!"
     }
 
-
-    @Test
-    fun `regular mode for H2 with DbConnectionConfig`() {
-        val url = "jdbc:h2:mem:testDatabase"
-        val username = "sa"
-        val password = ""
-
-        val dbConfig = DbConnectionConfig(url, username, password)
-
-        val df = DataFrame.readSqlQuery(dbConfig, "SELECT 1")
-        df.rowsCount() shouldBe 1
-    }
-
-    @Test
-    fun `regular mode for H2 with Connection`() {
-        val url = "jdbc:h2:mem:testDatabase"
-        val username = "sa"
-        val password = ""
-
-        DriverManager.getConnection(url, username, password).use { connection ->
-            val df = DataFrame.readSqlQuery(connection, "SELECT 1")
-            df.rowsCount() shouldBe 1
-        }
-    }
-
     // helper object created for API testing purposes
     object CustomDB : H2(MySql)