import { type SelectableValue } from '@grafana/data';
import { type QueryEditorFunctionExpression, type QueryEditorFunctionParameterExpression, type QueryEditorGroupByExpression, type QueryEditorPropertyExpression } from '../expressions';
import { type SQLExpression } from '../types';
export declare function createSelectClause(sqlColumns: NonNullable<SQLExpression['columns']>): string;
export declare const haveColumns: (columns: SQLExpression["columns"]) => columns is NonNullable<SQLExpression["columns"]>;
/**
 * Creates a GroupByExpression for a specified field
 */
export declare function setGroupByField(field?: string): QueryEditorGroupByExpression;
/**
 * Creates a PropertyExpression for a specified field
 */
export declare function setPropertyField(field?: string): QueryEditorPropertyExpression;
export declare function createFunctionField(functionName?: string): QueryEditorFunctionExpression;
/**
 * Retrieves the column value from a QueryEditorFunctionParameterExpression object.
 *
 * @param column - The QueryEditorFunctionParameterExpression object representing the column.
 * @returns The column value as a SelectableValue<string> or null if the column is undefined or null.
 */
export declare function getColumnValue(column?: QueryEditorFunctionParameterExpression | QueryEditorFunctionExpression): SelectableValue<string> | null;