MyCATApache/Mycat-Server · error · IllegalArgumentException

sql 注释 语法错误

Error message

sql 注释 语法错误

What it means

StringUtil.getTableName scans a SQL string to find the table name, skipping block comments. If it encounters '/*' with no closing '*/' later in the string (a malformed comment), it throws IllegalArgumentException('sql 注释 语法错误' — 'SQL comment syntax error').

Solutions

1. Close the block comment with '*/' in the SQL string
2. Replace the unterminated comment with '-- ' line comment or remove it
3. If SQL comes from a template/log truncation, ensure the full statement is passed to getTableName
4. Note the scan condition requires pos+4 < sql.length(); very short trailing input can also land here — keep comments well-formed

Example fix

// before
String sql = "select * from t1 /* test";
// after
String sql = "select * from t1 /* test */";

static boolean hasBalancedBlockComments(String sql){
    if (sql == null) return true;
    int open = 0;
    for (int i = 0; i < sql.length()-1; i++) {
        if (sql.startsWith("/*", i)) { open++; i++; }
        else if (sql.startsWith("*/", i)) { open--; i++; if (open < 0) return false; }
    }
    return open == 0;
}

try { table = StringUtil.getTableName(sql); }
catch (IllegalArgumentException e) { throw new IllegalArgumentException("SQL contains unterminated /* comment", e); }

When it happens

Trigger: Passing SQL whose '/*' comment is never closed, e.g. getTableName("select * from t1 /* hint") — the code detects '*/' is absent and aborts.

Common situations: Hand-written hints like /*+index*/ accidentally cut off by string truncation or editors; generated SQL where a comment template failed to close; copy/paste dropping the tail of the query.

Understand the failure class

Background: "Invalid ... format", "must be in format X", "does not look like a ..." — invalid argument format errors across CLI tools and libraries — this error's family across 17 libraries.

Related errors

• toString(buf)
• outside range [ , ]
• Interval year-month string was null
• Interval string does not match year-month format of 'y-m':
• Error parsing interval year-month string:

AI-assisted analysis of MyCATApache/Mycat-Server@65f8d8beb7 (2026-09-11). Data as JSON: /api/errors/d77a105833d9afc1. Report an issue: GitHub.

Appendix: source

Thrown at src/main/java/io/mycat/util/StringUtil.java:503

        } else
        {
            sql=oriSql;
        }
		int pos = 0;
		boolean insertFound = false;
		boolean intoFound = false;
		int tableStartIndx = -1;
		int tableEndIndex = -1;
		while (pos < sql.length()) {
			char ch = sql.charAt(pos);
			// 忽略处理注释 /* */ BEN
			if(ch == '/' &&  pos+4 < sql.length() && sql.charAt(pos+1) == '*') {
				if(sql.substring(pos+2).indexOf("*/") != -1) {
					pos += sql.substring(pos+2).indexOf("*/")+4;
					continue;
				} else {
					// 不应该发生这类情况。
					throw new IllegalArgumentException("sql 注释 语法错误");
				}
			} else if (ch <= ' ' || ch == '(' || ch=='`') {//
				if (tableStartIndx > 0) {
					tableEndIndex = pos;
					break;
				} else {
					pos++;
					continue;
				}
			} else if (ch == 'i' || ch == 'I') {
				if (intoFound) {
					if (tableStartIndx == -1 && ch!='`') {
						tableStartIndx = pos;
					}
					pos++;
				} else if (insertFound) {// into start
					// 必须全部都为INTO才认为是into
					if(pos+5 < sql.length() && (sql.charAt(pos+1) == 'n' || sql.charAt(pos+1) == 'N') && (sql.charAt(pos+2) == 't' || sql.charAt(pos+2) == 'T') && (sql.charAt(pos+3) == 'o' || sql.charAt(pos+3) == 'O') && (sql.charAt(pos+4) <= ' ')) {

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