/**
 * The set of column types understood by the schema grammars. Each maps to a
 * `type<Name>` method in the grammar, so adding a new type means adding a case
 * here plus the corresponding grammar method(s).
 */
export type ColumnType = 'char' | 'string' | 'text' | 'mediumText' | 'longText' | 'integer' | 'unsignedInteger' | 'bigInteger' | 'unsignedBigInteger' | 'smallInteger' | 'tinyInteger' | 'increments' | 'bigIncrements' | 'boolean' | 'float' | 'double' | 'decimal' | 'date' | 'dateTime' | 'time' | 'timestamp' | 'json' | 'jsonb' | 'uuid' | 'integerArray';
/**
 * A raw, unescaped SQL fragment. Use it when a modifier value must be emitted
 * verbatim (e.g. a function call in a DEFAULT clause):
 *
 *   table.timestamp('createdAt').default(new SchemaExpression('NOW()'))
 */
export declare class SchemaExpression {
    readonly value: string;
    constructor(value: string);
}
/**
 * Fluent description of a single table column. Column methods on the Blueprint
 * (`table.string(...)`, `table.integer(...)`, …) create one of these and return
 * it, so the caller can chain modifiers exactly like Laravel:
 *
 *   table.string('email', 150).nullable().unique()
 *   table.integer('status').default(1)
 *   table.timestamp('createdAt').useCurrent()
 */
export declare class ColumnDefinition {
    name: string;
    type: ColumnType;
    length?: number;
    total?: number;
    places?: number;
    isNullable: boolean;
    hasDefault: boolean;
    defaultValue: any;
    isUnsigned: boolean;
    isAutoIncrement: boolean;
    isPrimary: boolean;
    isUnique: boolean;
    isIndex: boolean;
    useCurrentTimestamp: boolean;
    useCurrentOnUpdateTimestamp: boolean;
    columnComment?: string;
    afterColumn?: string;
    isChange: boolean;
    constructor(name: string, type: ColumnType, attributes?: Partial<ColumnDefinition>);
    /** Marks the column as nullable (Laravel columns are NOT NULL by default). */
    nullable(value?: boolean): this;
    /** Explicitly marks the column NOT NULL. */
    notNullable(): this;
    /** Sets the column DEFAULT value. Pass a SchemaExpression for raw SQL. */
    default(value: any): this;
    /** Marks an integer column UNSIGNED (no-op on engines without unsigned types). */
    unsigned(): this;
    /** Marks the column auto-incrementing (implies a primary key). */
    autoIncrement(): this;
    /** Adds this column to the table primary key. */
    primary(): this;
    /** Adds a single-column UNIQUE constraint. */
    unique(): this;
    /** Adds a single-column index. */
    index(): this;
    /** Uses CURRENT_TIMESTAMP as the column default. */
    useCurrent(): this;
    /** Uses CURRENT_TIMESTAMP when the row is updated (MySQL ON UPDATE). */
    useCurrentOnUpdate(): this;
    /** Attaches a column comment (emitted by engines that support it). */
    comment(comment: string): this;
    /** Positions the column after another one (MySQL ADD COLUMN … AFTER). */
    after(column: string): this;
    /** Marks the column as a modification of an existing one (Schema.table change). */
    change(): this;
}