aspnetboilerplate/aspnetboilerplate · error · ArgumentException

' ' is a key field and cannot be ignored.

Error message

'{0}' is a key field and cannot be ignored.

What it means

Guard in MemberMap.Ignore(): the member {0} currently has a KeyType other than NotAKey and SlapperIdentifierKey, meaning it is an active mapped key. ABP Dapper forbids ignoring a key field because doing so would silently drop it from generated SQL, so the fluent Ignore() call is aborted with this ArgumentException.

Solutions

1. Clear or change the key assignment on this member before calling Ignore(), so its KeyType is NotAKey.
2. Ignore a different, non-key property instead of the key field {0}.
3. If the member should no longer be a key, restructure the ClassMap so the key is mapped on another property.

When it happens

Trigger: Thrown at src/Abp.Dapper/Dapper-Extensions/Mapper/MemberMap.cs:183 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of aspnetboilerplate/aspnetboilerplate@2323c13a15 (2026-09-08). Data as JSON: /api/errors/a7af6b84d28d680d. Report an issue: GitHub.

Appendix: source

Thrown at src/Abp.Dapper/Dapper-Extensions/Mapper/MemberMap.cs:183

            }

            if (!string.IsNullOrEmpty(SequenceName) && keyType != KeyType.SequenceIdentity)
            {
                throw new ArgumentException(string.Format("'{0}' cannot be made a key field. ", Name));
            }

            KeyType = keyType;
            return this;
        }

        /// <summary>
        /// Fluently sets the ignore status of the property.
        /// </summary>
        public MemberMap Ignore()
        {
            if (KeyType != KeyType.NotAKey && KeyType != KeyType.SlapperIdentifierKey)
            {
                throw new ArgumentException(string.Format("'{0}' is a key field and cannot be ignored.", Name));
            }

            Ignored = true;
            return this;
        }

        /// <summary>
        /// Fluently sets the read-only status of the property.
        /// </summary>
        public MemberMap ReadOnly()
        {
            if (KeyType != KeyType.NotAKey && KeyType != KeyType.SlapperIdentifierKey)
            {
                throw new ArgumentException(string.Format("'{0}' is a key field and cannot be marked readonly.", Name));
            }

            IsReadOnly = true;
            return this;

View on GitHub (pinned to 2323c13a15)