SQL code completion boosts developer productivity by predicting missing snippets from editing SQL contexts. However, existing solutions yield low acceptance since they cannot abstain when no suggestion is needed and lack SQL-specific training. To address both limitations, we introduce PACE-SQL, a preference-aligned framework that improves SQL completion accuracy and user preference alignment. We build two datasets with completion and abstention samples: WeSQL-1.5M from real-world interaction logs to capture authentic user preferences, and OpenSQL-FIM from public SQL corpora. We adopt continual pretraining and supervised fine-tuning to improve completion quality, and design a reward function in the reinforcement learning to enhance alignment with user preferences. Experiments show PACE-SQL improves Exact Match and Edit Similarity scores by 9.67% and 7.52% over the best baseline on WeSQL-1.5M and raises online user acceptance rate from 5% to 29%.