/**
 * Column Operations Module
 * Handles column comparison, addition, modification, and dropping logic
 */
import type { ILegacySyncOptions, TArray } from '../../types';
import { type SyncDbSide } from '../syncClient';
import type { Client } from 'pg';
interface ColumnInfo {
    table_name: string;
    column_name: string;
    data_type: string;
    resolved_type?: string;
    udt_schema?: string;
    udt_name?: string;
    character_maximum_length?: number;
    is_nullable: 'YES' | 'NO';
    column_default?: string;
    ordinal_position: number;
}
export declare class ColumnOperations {
    private sourceClient;
    private targetClient;
    private options;
    constructor(sourceClient: Client, targetClient: Client, options: ILegacySyncOptions);
    /**
     * Get all columns from a schema on the given database.
     */
    getColumns(side: SyncDbSide): Promise<TArray<ColumnInfo>>;
    /**
     * Group columns by table name
     */
    groupColumnsByTable(columns: TArray<ColumnInfo>): Record<string, TArray<ColumnInfo>>;
    /**
     * Generate column definition string
     */
    generateColumnDefinition(column: ColumnInfo): string;
    /**
     * Generate ALTER COLUMN statement for modifications
     */
    generateAlterColumnStatement(tableName: string, sourceCol: ColumnInfo, targetCol: ColumnInfo): string;
    /**
     * Handle columns that need to be dropped
     */
    handleColumnsToDrop(tableName: string, columnsToDrop: TArray<ColumnInfo>, alterStatements: TArray<string>): void;
    /**
     * Handle column modification with detailed comments
     */
    handleColumnModification(tableName: string, sourceCol: ColumnInfo, targetCol: ColumnInfo, alterStatements: TArray<string>): void;
    /**
     * Handle columns that need to be added or modified
     */
    private isLikelyForeignKeyColumn;
    private isNumericIdentifierType;
    private requiresManualBackfill;
    handleColumnsToAddOrModify(tableName: string, sourceTableCols: TArray<ColumnInfo>, targetTableCols: TArray<ColumnInfo>, alterStatements: TArray<string>): void;
    /**
     * Get default value for a data type
     */
    private getDefaultValueForType;
    /**
     * Generate column operations for schema sync
     */
    generateColumnOperations(): Promise<TArray<string>>;
}
export {};
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