Mapping Warnings

After objects are mapped for comparison and synchronization, you may encounter warnings on the Mapping page of the Data Comparison wizard. The warnings may be divided into two groups. They are table-level warnings and column level warnings.

Table-level warnings are displayed as Caution Icon icons in the column with check boxes on the Mapping page of the Data Comparison wizard. Object pairs with table-level warnings are not compared. They are displayed with the Caution Icon icon instead of a check box in the Data Comparison document.

Mapping Page

Note: Actual document look may slightly vary from the above image depending on the product you use.

Column-level warnings are displayed as the Caution Icon icon in the Columns in Comparison column on the Mapping page of the Data Comparison wizard. They also appear in the Target column in the Column Mapping dialog box. Such warnings mean that some columns of a compared object pair cannot be compared because of type incompatibility or that you may encounter data loss when synchronizing data.

To read the warning messages, point to the warning icon. All warnings for this object will appear in the hint.

The following table contains information about table-level warnings and ways to remove them.

Warning Description
No columns to compare. It means, there are no columns with the same name in this pair of tables (views). To compare them you should map the columns manually. For more information about the column mapping, see Mapping Columns
Objects to compare have no key column. It means that custom comparison key is used but is not set. You should mark at least one column pair as comparison key. For more information visit Setting Comparison Key

The following table contains information about column-level warnings.

Warning Description
Cannot convert parameter value to “{0}” data type. This warning appears when a query with parameter is run in a SQL document and the form asks for a value of the specific type for this parameter, but a value of a different type was entered. This warning is critical. To solve it, you should enter correct parameter value.
Conversion is possible, but may fail in case of incompatible data. Conversion between columns “{0}” and “{1}” is possible, but may fail in case of incompatible data. This warning appears if columns of very similar, but yet different types are mapped, for example, CHARACTER(255) and CHARACTER VARYING(255). This warning is not critical for comparison, but it’s of medium importance for synchronization. To solve this problem, you should use custom query with explicit conversion to the target type in the source.
Columns have different collations. Columns “{0}” and “{1}” have different collations. This warning appears if mapped columns have different collation. This warning may result in incorrect comparison of values. To solve it, you should use custom query in the source that sets the collation to the one that is used in target explicitly.
Columns are enum types. Columns “{0}” and “{1}” are enum types and may not be converted. This warning appears when Enum is used as column data type. The application does not support Enum data type. It is critical. To solve it, you should use custom query in source and target that will convert such types to the supported data types explicitly. In this case comparison will be possible, but synchronization will not.
Columns have different precisions. Columns “{0}” and “{1}” have different precisions, migrating the data may cause overflows. This warning appears if columns have different precision. It is not critical for comparison, but has medium importance for synchronization. To solve it, you should use custom query in source that will perform explicit conversion to the target data type.
Date or time columns have different data format. Date or time columns “{0}” and “{1}” have different data format, migrating the data may cause truncation. This warning appears if date and time in mapped columns are stored in different format. The importance of this warning is medium. To solve it, you should use custom query in source that will convert the type to the one used in target.
Decimal columns have different precisions or scales. Decimal columns “{0}” and “{1}” have different precisions or scales, migrating the data may cause rounding or overflows. This warning appears if decimal columns have different precision or scale. It is not critical for comparison and is of medium importance for synchronization. To solve it, you should use custom query in source that will convert the type to the one used in target.
Decimal and Integer columns have different precisions and scales. Decimal and Integer columns “{0}” and “{1}” have different precisions and scales, migrating the data may cause rounding or overflows. This warning appears if decimal and integer columns have different precision and scale. It is not critical for comparison and is of medium importance for synchronization. To solve it, you should use custom query in source that will convert the type to the one used in target.
Float and Integer columns have different precisions and scales. Float and Integer columns “{0}” and “{1}” have different precisions and scales, migrating the data may cause rounding or overflows. This warning appears if float and integer columns have different precision and scale. It is not critical for comparison and is of medium importance for synchronization. To solve it, you should use custom query in source that will convert the type to the one used in target.
Numeric columns have different precisions. Numeric columns “{0}” and “{1}” have different precisions, migrating the data may cause rounding. This warning appears if numeric columns have different precision. It is not critical for comparison and is of medium importance for synchronization. To solve it, you should use custom query in source that will convert the type to the one used in target.
Columns have different sizes. Columns “{0}” and “{1}” have different sizes, migrating the data may cause truncation. This warning appears if columns have different size, for example, CHARACTER(255) and CHARACTER(300). It is not critical for comparison and is of medium importance for synchronization. To solve it, you should use custom query in source that will convert the type to the one used in target.
Columns “{0}” and “{1}” have incompatible types. This warning appears if data types in mapped columns cannot be converted. It is critical. To solve it, use custom query with explicit conversion to the needed data type, if such conversion is possible.
Source column allows Nulls which can not be stored in target. Source column “{0}” allows Nulls which can not be stored in target column “{1}”, migrating the data may cause an error. This warning appears if source column allows Nulls which cannot be stored in target. It is not critical at all for comparison and is of medium importance for synchronization. To solve it, you should use custom query in source that will exclude rows with Null or will replace them with another value.
There are unsupported types in the columns. This warning appears if there are unsupported types in columns. It is critical. To solve it, you should use custom query with explicit conversion to the supported data type if such conversion is possible.
Maybe you are trying to connect to PostgreSQL server version 7. This server version is not supported. Connection error: “{0}” This warning appears if an error occurred on connection attempt, for example, if server version is not supported. It is critical. To solve it, you should check server version and make sure it is configured correctly, also check if the parameters specified in dbForge connection dialog box are correct.
Bit value can contain only 0 and 1 digits. This warning appears if on reading data in bit types a value different from 0 and 1 is found. Such error can occur if explicit conversation to bit type is avalaible in source of target. It is critical - comparison of such table is impossible. To solve it, you should correct conversion.
Support is done for PostgreSQL versions starting 8.3. The {0} version of the PostgreSQL server (Host: {1} Port: {2}) is not supported. This warning appears if unsupported server version is found on connection. It is critical. To solve the problem, you should contact Devart support and inform about the PostgreSQL server version that is not supported.

Note:

You may exclude columns from comparison and synchronization either by unmapping them or by clearing check boxes in the first column of Select columns for comparison grid on the Column Mapping dialog box.