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Bindings

Bindings

Flecto's binding mechanism allows you to fluently connect filters to specific database columns, forming the foundation of a dynamic and type-safe query.

This is done using the FlectoBuilder class and its fluent methods such as BindNumeric, BindString, BindBool, Search, and others. Each method binds a provided filter instance to one or more SQL column names, safely translating user inputs into parameterized SQL expressions.

Basic Usage

var builder = new FlectoBuilder("employee", DialectType.Postgres)
    .Search(r.Search, "first_name", "last_name", "middle_name", "notes")
    .BindNumeric(r.Id, "id")
    .BindString(r.Name, "first_name")
    .BindNumeric(r.Salary, "salary");

var (sqlCount, parametersCount) = builder
    .Clone()
    .SelectCount()
    .Build();

var totalRecords = await connection.QueryFirstAsync<int>(sqlCount, parametersCount);

var (sql, parameters) = builder
    .SelectAll()
    .ApplyPaging(r.Paging)
    .Build();

var employees = await connection.QueryAsync<Employee>(sql, parameters);

Key Binding Methods

  • BindNumeric(filter, column) — binds a NumericFilter<T> to a column.
  • BindString(filter, column) — binds a StringFilter.
  • BindBool(filter, column) — binds a BoolFilter.
  • BindGuid(filter, column) — binds a GuidFilter.
  • BindDate(filter, column) — binds a DateFilter.
  • BindEnum(filter, column) — binds an EnumFilter<T>.
  • BindFlagsEnum(filter, column) — binds a [Flags] enum filter.
  • Search(searchFilter, columns...) — applies a search filter using ILIKE or full-text search depending on dialect.

All binding methods automatically:

  • Perform null-checks and skip filters not provided;
  • Build every column with table prefix: table.column
  • Safely parameterize SQL values to prevent SQL injection.
  • Validate filters internally (via EnsureValid) and validate table and column(s) naming;

Query Composition Notes

  • Currently supports only single-table queries;
  • All Bind* and Search methods are translated into the WHERE clause using logical AND;
  • Multiple Bind* calls will append conditions conjunctively;
  • Selection options include:
  • SelectAll() — SELECT *
  • SelectCount() — SELECT COUNT(*) with ORDER BY skipped
  • Select(columns) — SELECT specific columns
  • not allow manual select logic at the moment

Optional Clone and Count

You can safely clone a builder mid-way and use it to perform a COUNT(*) query:

var (sqlCount, parametersCount) = builder.Clone().SelectCount().Build();

This helps compute total pagination values before fetching the actual page.

💡 Want to return paginated results with metadata?

→ Check out Usages to learn how to wrap Flecto queries using SearchResult<T> and return structured responses.