MySQL 8.0 Reference Manual 12.7 Date and Time Functions .............................................................................................. 2150 12.8 String Functions and Operators ..................................................................................... 2171 12.8.1 String Comparison Functions and Operators ........................................................ 2186 12.8.2 Regular Expressions ........................................................................................... 2190 12.8.3 Character Set and Collation of Function Results .................................................. 2200 12.9 What Calendar Is Used By MySQL? .............................................................................. 2202 12.10 Full-Text Search Functions .......................................................................................... 2202 12.10.1 Natural Language Full-Text Searches ................................................................ 2203 12.10.2 Boolean Full-Text Searches .............................................................................. 2207 12.10.3 Full-Text Searches with Query Expansion .......................................................... 2212 12.10.4 Full-Text Stopwords .......................................................................................... 2213 12.10.5 Full-Text Restrictions ........................................................................................ 2218 12.10.6 Fine-Tuning MySQL Full-Text Search ................................................................ 2218 12.10.7 Adding a User-Defined Collation for Full-Text Indexing ....................................... 2221 12.10.8 ngram Full-Text Parser ..................................................................................... 2223 12.10.9 MeCab Full-Text Parser Plugin ......................................................................... 2226 12.11 Cast Functions and Operators ..................................................................................... 2230 12.12 XML Functions ............................................................................................................ 2247 12.13 Bit Functions and Operators ........................................................................................ 2258 12.14 Encryption and Compression Functions ........................................................................ 2271 12.15 Locking Functions ....................................................................................................... 2277 12.16 Information Functions .................................................................................................. 2279 12.17 Spatial Analysis Functions ........................................................................................... 2290 12.17.1 Spatial Function Reference ............................................................................... 2291 12.17.2 Argument Handling by Spatial Functions ............................................................ 2295 12.17.3 Functions That Create Geometry Values from WKT Values ................................ 2295 12.17.4 Functions That Create Geometry Values from WKB Values ................................ 2298 12.17.5 MySQL-Specific Functions That Create Geometry Values ................................... 2299 12.17.6 Geometry Format Conversion Functions ............................................................ 2301 12.17.7 Geometry Property Functions ............................................................................ 2303 12.17.8 Spatial Operator Functions ................................................................................ 2317 12.17.9 Functions That Test Spatial Relations Between Geometry Objects ...................... 2325 12.17.10 Spatial Geohash Functions ............................................................................. 2333 12.17.11 Spatial GeoJSON Functions ............................................................................ 2335 12.17.12 Spatial Aggregate Functions ............................................................................ 2337 12.17.13 Spatial Convenience Functions ....................................................................... 2339 12.18 JSON Functions .......................................................................................................... 2344 12.18.1 JSON Function Reference ................................................................................ 2344 12.18.2 Functions That Create JSON Values ................................................................. 2346 12.18.3 Functions That Search JSON Values ................................................................ 2347 12.18.4 Functions That Modify JSON Values ................................................................. 2363 12.18.5 Functions That Return JSON Value Attributes .................................................... 2373 12.18.6 JSON Table Functions ...................................................................................... 2376 12.18.7 JSON Schema Validation Functions .................................................................. 2381 12.18.8 JSON Utility Functions ...................................................................................... 2387 12.19 Functions Used with Global Transaction Identifiers (GTIDs) ........................................... 2392 12.20 Aggregate Functions ................................................................................................... 2394 12.20.1 Aggregate Function Descriptions ....................................................................... 2394 12.20.2 GROUP BY Modifiers ....................................................................................... 2405 12.20.3 MySQL Handling of GROUP BY ....................................................................... 2411 12.20.4 Detection of Functional Dependence ................................................................. 2414 12.21 Window Functions ....................................................................................................... 2417 12.21.1 Window Function Descriptions .......................................................................... 2418 12.21.2 Window Function Concepts and Syntax ............................................................. 2424 xiii