Support ZEROFILL MySqlDecimal columns. Fixes #1354

Author: bgrainger

src/MySqlConnector/MySqlDecimal.cs

@@ -46,7 +46,7 @@ internal MySqlDecimal(string value)
 		throw new FormatException($"Could not parse the value as a MySqlDecimal: {value}");
 	}
 
-	private static readonly Regex s_pattern = new(@"^-?([1-9][0-9]*|0)(\.([0-9]+))?$");
+	private static readonly Regex s_pattern = new(@"^-?([0-9]+)(\.([0-9]+))?$");
 
 	private readonly string m_value;
 }

tests/IntegrationTests/InsertTests.cs

@@ -514,6 +514,40 @@ public void ReadMySqlDecimalUsingReader(bool prepare)
 #endif
 	}
 
+	[Theory]
+	[InlineData(false)]
+	[InlineData(true)]
+	public void ReadMySqlDecimalZeroFill(bool prepare)
+	{
+		using MySqlConnection connection = new MySqlConnection(AppConfig.ConnectionString);
+		connection.Open();
+		connection.Execute("""
+			drop table if exists mysql_decimal_zerofill;
+			create table mysql_decimal_zerofill(rowid integer not null primary key auto_increment, value decimal(20, 10) zerofill);
+			insert into mysql_decimal_zerofill(value) values(0),(1),(0.1);
+			""");
+
+		using var cmd = connection.CreateCommand();
+		cmd.CommandText = @"select value from mysql_decimal_zerofill order by rowid;";
+		if (prepare)
+			cmd.Prepare();
+		using var reader = cmd.ExecuteReader();
+
+		Assert.True(reader.Read());
+		Assert.Equal("0000000000.0000000000", reader.GetMySqlDecimal("value").ToString());
+		Assert.Equal(0m, reader.GetDecimal(0));
+
+		Assert.True(reader.Read());
+		Assert.Equal("0000000001.0000000000", reader.GetMySqlDecimal("value").ToString());
+		Assert.Equal(1m, reader.GetDecimal(0));
+
+		Assert.True(reader.Read());
+		Assert.Equal("0000000000.1000000000", reader.GetMySqlDecimal("value").ToString());
+		Assert.Equal(0.1m, reader.GetDecimal(0));
+
+		Assert.False(reader.Read());
+	}
+
 	[Theory]
 	[InlineData(false)]
 	[InlineData(true)]

tests/MySqlConnector.Tests/MySqlDecimalTests.cs

@@ -30,20 +30,6 @@ public void TestToDecimal()
 		Assert.Equal(doubleVal, mySqlDecimal.Value);
 	}
 
-	[Fact]
-	public void TestInvalidFormatWithDecimalPostive()
-	{
-		var invalidValue = "0323.323";
-		Assert.Throws<FormatException>(() => new MySqlDecimal(invalidValue));
-	}
-
-	[Fact]
-	public void TestInvalidFormatWithDecimalNegative()
-	{
-		var invalidValue = "-0323.323";
-		Assert.Throws<FormatException>(() => new MySqlDecimal(invalidValue));
-	}
-
 	[Fact]
 	public void TestValidFormatWithDecimalNegative68Length()
 	{
@@ -109,6 +95,10 @@ public void TestValidFormatWithDecimalNegative67Length()
 	[InlineData("-0.1")]
 	[InlineData("1.0")]
 	[InlineData("1.23")]
+	[InlineData("00")]
+	[InlineData("01")]
+	[InlineData("0323.323")]
+	[InlineData("-0323.323")]
 	[InlineData("12345678901234567890123456789012345678901234567890123456789012345")]
 	[InlineData("-12345678901234567890123456789012345678901234567890123456789012345")]
 	[InlineData("12345678901234567890123456789012345.012345678901234567890123456789")]
@@ -120,8 +110,6 @@ public void ValidDecimalValues(string input) =>
 	[InlineData("")]
 	[InlineData("-0")]
 	[InlineData("-0.0")]
-	[InlineData("00")]
-	[InlineData("01")]
 	[InlineData("123456789012345678901234567890123456789012345678901234567890123456")]
 	[InlineData("-123456789012345678901234567890123456789012345678901234567890123456")]
 	[InlineData("123456789012345678901234567890123456.012345678901234567890123456789")]