001package gudusoft.gsqlparser.resolver2;
002
003/**
004 * Three-level column existence check.
005 * Used for determining whether a column exists in a namespace
006 * and whether metadata is available to make that determination.
007 */
008public enum ColumnLevel {
009    /**
010     * Column definitely exists (confirmed by metadata).
011     * Confidence: 1.0
012     */
013    EXISTS,
014
015    /**
016     * Column might exist but cannot be confirmed (no metadata).
017     * This is common for SELECT * scenarios without schema info.
018     * Confidence: typically 0.5-0.9 depending on evidence
019     */
020    MAYBE,
021
022    /**
023     * Column definitely does not exist (metadata confirms absence).
024     * Confidence: 0.0
025     */
026    NOT_EXISTS
027}